Станислаус өзені: Калифорнияның су жүйесі мен географиясы

River in north central California, US

About two thirds of the Stanislaus River flow originates as snowmelt between the months of April and July, although its highest peak flows tend to occur during winter rains. The water flow varies widely from year to year, with a historic maximum of or in the 1983 water year and a minimum of or in 1977. Water diversions for irrigation and regulation by reservoirs have significantly lowered the mean flow of the lower Stanislaus River, smoothed out seasonal variations, and increased the dry season baseflow. The United States Geological Survey (USGS) stream gage at Ripon, 15 mile (24 km) from the mouth, recorded an annual flow of between 1941 and 1978; after New Melones Dam was built the annual flow between 1978 and 2013 was and the lowest monthly mean was in August 1977. After the dam was built, the highest peak was on February 28, 1997, and the lowest monthly mean was in September 2016.]] The Stanislaus River watershed drains and is divided into two distinct sections – the mountainous upper watershed, where the vast majority of its flow originates, and the narrow, heavily developed lower watershed where it flows across the San Joaquin Valley. Goodwin Dam has traditionally been considered the dividing line between the upper and lower watersheds. Elevations in the watershed range from less than 15 feet (5 m) at the confluence with the San Joaquin River to over 10000 feet (3048 m) in the high Sierra Nevada. Annual precipitation varies from in the valley regions to or more at higher elevations; at elevations above 5000 feet (1524 m) most precipitation falls as snow. The upper watershed comprises 90 percent of the total area and supplies a commensurate proportion of the river flow. Stretching from the foothill to alpine regions of the Sierra Nevada, it consists of rugged narrow canyons and ridges with an average local relief of 2000 feet (610 m) or more from river to rim. The vast majority of the upper basin is either undeveloped or commercial timber land, with very small areas of agriculture, ranching, and mountain meadows above the tree line. The higher elevations are mostly federal Forest Service land and designated wilderness, while the middle elevations are a patchwork of state, federal and privately owned land. Much of the private timber land has been subject to checker board clearcutting, which has greatly fragmented wildlife habitat. The lower Stanislaus River watershed comprises only about one tenth of the total area and is used mainly for agriculture (61 percent) and urban development (34 percent), with minimal open space. Major communities near the lower river include (from upstream to downstream) Copperopolis, Knights Ferry, East Oakdale, Oakdale, Riverbank, Escalon, Salida and Ripon. As the mountains rose the Stanislaus River established its modern course, carrying away the volcanic material that had filled the ancestral canyon. This orogeny coincided with a second period of volcanic activity, during which lava flows displaced the Stanislaus River course several times where it flows through the foothills, causing it to carve new canyons through underlying sedimentary rock. The lava flows are today known as the Stanislaus Formation, and are most visible as the caprock layer of the distinctive "table mountains" around present day New Melones Lake. As both uplift and erosion continued, the Stanislaus River gradually carved the rugged canyons it flows through today, and contributed to the vast alluvial deposits that make up the flat floor of the Central Valley. Most of the erosion that shaped the modern Stanislaus River basin is believed to have occurred during glacial and interglacial periods in the Pleistocene, starting about 1 million years ago. During the ice ages California had a much wetter climate; average river flows in the past may have been as high as what is considered "flood stage" today. The climate was also cold enough to support large glaciers in the Sierra Nevada at elevations above 4000 feet (1219 m). The Miwok had a predominantly hunter gatherer lifestyle, although they also practiced some primitive agriculture and controlled burning of grassland to enhance their hunting grounds. Native Americans of the region did not form one large nation; rather, they lived in "tribelets" of between 100 and 500 people. One group associated with the Stanislaus River was the "Walla" or "Wal li" (a native term meaning "digger" or "toward the earth") who lived in the hills between the Stanislaus and Tuolumne Rivers. Fray Pedro Muñoz, traveling with Moraga, wrote of "immense quantities of wild grape vines" along the Guadalupe River. In 1808, Moraga returned to the area to search for suitable mission sites, but was not successful. The river later became known as Río de los Laquisimes, possibly derived from a Native American name for the river or surrounding area. Although the Spanish ultimately did not establish any missions in the Central Valley, they forcibly took thousands of Native Americans to missions along the coast, where they were converted to Catholicism and subjected to agricultural labor. Mission San José was the destination of many Miwok from the Laquisimes River area. American explorers also visited the Laquisimes River country starting in the 1820s, in search of beaver and otter pelts. The fur trappers included renowned mountain men Jedediah Smith, William Henry Ashley, and Ewing Young, who explored the area in the period between 1825 and 1830. In the spring of 1827 Smith's party camped on the Laquisimes River near present day Oakdale, having reportedly cached of beaver pelts nearby. Smith called the river the "Appelamminy". On May 20, Smith and two other men set out along the Laquisimes to attempt a crossing of the Sierra Nevada. About a week later, after having made their way up the rugged North Fork canyon, they crossed Ebbetts Pass, becoming the first people of European descent to cross the Sierra. After the initial defeat, Vallejo returned with a force of "107 soldiers, some citizens, and at least fifty mission Indian militiamen" armed with muskets and cannon, but again fought to a draw. Vallejo set fire to vegetation along the river banks to draw out the opposition, but Estanislao and his fighters escaped, and continued to raid Mexican settlements through that winter. According to popular legend, Estanislao would carve an "S" in a tree after his attacks, and was an inspiration for the fictional character Zorro. In June 1829 Vallejo finally defeated him on the Laquisimes River. At least one factor in its decline was a massive flood that winter; William Stout, one of the town's founders, wrote that the Stanislaus was "three miles wide" in January 1848. The influence of American settlement ultimately led to the Bear Flag Revolt, after which California became part of the United States in 1848. In the same year, gold was discovered on the American River, starting the California Gold Rush. Although gold mining was initially concentrated on the American and other rivers to the north, attention was drawn to the Stanislaus in August 1848 after a Native American party under Charles Weber discovered gold on the river. The entire mining camp of Dry Diggings (near today's Placerville), about 200 men in all, packed up and headed south to the Stanislaus River, and as news spread throughout the Gold Country, hundreds more arrived. Many miners traveling from the eastern United States arrived in California via the Sonora Pass, at the headwaters of the Middle Fork of the Stanislaus River. By 1849, as many as 10,000 miners had reached the Stanislaus River country. The Stanislaus was as productive a gold bearing stream as any in California; in the early days of the Gold Rush it was known as the "Southern Mines" because it was at the time the southernmost extent of the primary gold diggings. In 1848 William R. Ryan wrote that the mining camps along the Stanislaus River were "all of the poorest and most wretched description. Miners expected to profit within a short time and then leave these primitive conditions and return to their homes. There were numerous tents, good, bad, and indifferent, stores and gambling booths, shanties and open encampments; and miners busy everywhere." Initially, miners worked individual placer claims, but as the easily accessed gold played out, they teamed up to build extensive dam, ditch and flume systems that could more efficiently wash gold out of sediment, as well as supply water to gold bearing areas without a water source and provide water for irrigation. These represent some of the earliest water rights claims along the Stanislaus River. In 1851 the Tuolumne County Water Company was organized to divert water from the South Fork of the Stanislaus River; by 1853 it consisted of 80 mile (129 km) of canals serving as many as 1,800 miners and their claims. Water was supplied as far as Columbia and Sonora, 60 mile (97 km) to the south. The Columbia and Stanislaus River Company was formed in 1854 on the main stem of the Stanislaus River, in competition to the high rates charged by Tuolumne. They built a ditch at a cost of $1.5 million (five times the original estimate), went bankrupt shortly after, and was ultimately sold to the Tuolumne County Water Company at a small fraction of the original cost. These early waterworks were crudely built and often failed, sometimes with tragic results. Knights Ferry declined in influence as many of the departing miners settled around the farming community of Oakdale, several miles downstream. Historic records show that the majority of ranches and homesteads in the Stanislaus River area were established between the 1850s and 1890s by former gold seekers. During the late 1800s and early 1900s, development slowly moved higher into the Stanislaus watershed in large part due to improvement of the Sonora Pass Highway. The former wagon trail up the Stanislaus canyon had operated since 1864 as a toll road (Sonora Mono Toll Road) and was heavily traveled during the 1870s during the gold strike in Bodie. A number of trading posts and rest stops operated on both sides of Sonora Pass including Sugar Pine, Strawberry, Baker's Station, Leavitt's Station and Big Meadows. In the following decades, travel over Sonora Pass declined heavily. The road became part of the state highway system in 1901 and was improved in 1906 to service the construction of Relief Dam in the headwaters of the Stanislaus River. Today, most of the road has been replaced by the newer alignment of Highway 108. The new Dardanelle Bridge was built in 1933 to replace an older span constructed in 1864 and provide better access to the tourist areas. This bridge was believed to be the last known timber scissors truss in the United States. Both the resort and the bridge were destroyed in the 2018 Donnell Fire. There was also extensive logging done throughout the foothill area of the Stanislaus watershed, and several narrow gauge railroads penetrated into the foothills, including the Sugar Pine Railway or Strawberry Branch, which followed the Stanislaus' South Fork. Another line, the Sierra Railway's Angels Branch, connected Jamestown to Angels Camp and required a series of switchbacks to traverse the deep canyon of the Stanislaus River, an area now flooded by New Melones Lake. During the 1930s scenes for Robin Hood of El Dorado were filmed near the old Douglas Resort. In the 1970s several episodes of the Little House on the Prairie TV series were filmed at Donnell Vista, near Donnell Lake.

The Stanislaus River is one of the most heavily dammed and diverted rivers in California, relative to its size. There are a total of 28 major dams on the Stanislaus River and its tributaries with a combined storage capacity of more than 2.8 million acre feet (3.5 km3). are operated by various local irrigation districts, private power companies and federal agencies. Stanislaus River water flows are also a vital resource to maintain fisheries and recreational activities, dilute pollution, recharge groundwater, and control saline intrusion in the Sacramento–San Joaquin River Delta. The river is extremely over allocated, meaning that claims to its water far exceed supply. There are more than 160 separate water rights to the Stanislaus River totaling 19.7 million acre feet (24.3 km3), compared to the river's normal flow of 1.1 million acre feet (1.4 km3). Water rights on the Stanislaus River have traditionally been, and are still de jure subject to the prior appropriation method, where the oldest rights holders get first priority. However, after the completion of New Melones Dam in 1979, and especially due to drought in recent years, federal and local agencies have often been forced to compromise in order to divide limited Stanislaus River supplies between the many demands.

Farmers have been using water from the Stanislaus River since the Gold Rush, when water was diverted to small farms and vegetable gardens on homesteads. As the number of claimants on the river grew, farmers recognized they had to work together in order to effectively distribute the water. One of the first irrigation cooperatives formed on the Stanislaus River was formed by the Tulloch family in 1858, who built a diversion dam to supply farms in the area around Knight's Ferry. The Stanislaus and San Joaquin Water Company, formed by H. W. Cowell and N. S. Harrold in 1895, improved on this system, building 47 mile (76 km) of canals along the north side of the Stanislaus River and supplying water to some in Manteca and Oakdale. The OID service area is located on both sides of the Stanislaus River in Stanislaus County, and the SSJID is located on the north side of the river, in Stanislaus and San Joaquin Counties. Today, the districts irrigate a combined , Today, this area is one of the most productive agricultural regions of the United States; in 2014, Stanislaus and San Joaquin Counties produced a combined $7.6 billion of crops. Shortly after their formation, the districts issued $1.9 million in revenue bonds to finance the dam and canal infrastructure that would supply the land. In 1913 the districts built Goodwin Dam, about 2.5 mile (4 km) upstream of Knights Ferry, to divert water into their respective canals. They filed claims for of Stanislaus River water, divided evenly between the two districts. In the early years, maintaining a sufficient water supply in the summer was nearly impossible, because the Sierra snowpack usually melts out by mid June. Agriculture relied heavily on wells in the late summer when the river was low, and this could only support about of crops. The lower Stanislaus River was often completely dry in the summertime due to water diversions. The irrigation districts desperately needed water storage for the dry season, and a number of small off stream reservoirs were built, including Woodward Reservoir in 1916, though their benefit was limited at best. A severe drought in the 1930s demonstrated that Melones Reservoir, by itself, was too small to meet all the irrigation demands. The OID sank 25 deep wells between 1931 and 1938 to make up for the shortfall, but this depleted the local groundwater at an unsustainable rate. The $52 million Tri Dam project would mainly be financed by leasing hydro power rights at these dams to Pacific Gas & Electric Company (PG&E) for a 50 year period. After almost ten years of construction, Donnells and Beardsley Dam were completed in 1957, and Tulloch Dam completed in 1958. The three dams combined could store , more than tripling the water storage capacity on the Stanislaus River, and increased the reliable annual supply to almost However, they were unable to provide a sound economic justification for the project on flood control alone. In the 1950s, the U. S. Bureau of Reclamation proposed a much larger dam with a capacity of 2.4 million acre feet (3.0 km3), which would capture most of the extra floodwaters that the existing small irrigation dams could not hold. It would be a multi purpose unit of the Central Valley Project, providing irrigation, flood control, hydropower and fishery flows. Locals initially criticized the project, saying that it was too big, a waste of federal money, and the reservoir would never fill. There was also concern that the Bureau of Reclamation was attempting a "water grab" that would take the extra water to meet obligations outside the Stanislaus River Basin. However, after the Christmas flood of 1964 caused massive destruction along the Stanislaus River, New Melones gained political support. After federal funding was approved, construction started in 1966. The Stanislaus was for a time the most popular run in the western United States, and was valued for the spectacular scenery along its rugged limestone canyons. Friends of the River was formed to push a statewide ballot measure, Prop 17, that would have designated the Stanislaus as a National Wild and Scenic River and forestalled the construction of New Melones. Prop 17 was defeated by a narrow margin of voters, in part due to heavy lobbying by water agencies. Afterwards, dam opponents focused on limiting the level of the new reservoir, even as dam construction was completed in 1978. In May 1979 environmental activist Mark Dubois chained himself to a boulder in the Stanislaus Canyon, forcing federal authorities to either stop filling the lake or drown him. As a result, the state of California under Governor Jerry Brown (who also objected to New Melones on economic grounds) issued a temporary limit in November 1980 to keep the lake level below Parrott's Ferry Bridge, which marked the lower end of the Stanislaus whitewater. The federal government and some agencies which stood to benefit from the new dam derided the decision, arguing that to not fill the already completed dam was a waste of money and water. Heated debate continued until the 1982–1983 water years, California's wettest back to back seasons on record, when massive storms and snowpack swelled the river and filled the reservoir in under two years, a process originally projected to take eight years. In June 1983 New Melones Lake hit its highest level on record, nearly flowing over the emergency spillway. The floods demonstrated the value of the dam in preventing $50 million of property damage and capturing a huge volume of water that would otherwise have flowed into the ocean, prompting the state of California to lift the temporary limit. Since then, New Melones has struggled to fulfill its obligations to downstream water users; during droughts, the irrigation districts and the federal government have frequently fought over its water. One of the conditions of New Melones' construction was that the OID and SSJID be guaranteed the of water rights they had held since 1913. In addition, the Melones Project is obligated to provide water to the Stockton East Water District, which irrigates an additional north of the Stanislaus River, and the Central San Joaquin
Water Conservation District which irrigates
New Melones was a significant milestone in the history of American dam building. The battle over the Stanislaus River greatly increased the political influence of the river conservation movement, and public awareness of the environmental impact of large dam projects. In 1939 PG&E completed the much larger Stanislaus Powerhouse near the confluence of the Middle and North Forks. Water was diverted from the Middle Fork at Sand Bar Dam, and a 11.4 mile (18 km) long tunnel was drilled through the mountains to carry it to the powerhouse. Because the water is diverted so far upstream, it affords a head of over 1000 feet (305 m) to the Stanislaus Powerhouse; the much heavier flow of the Middle Fork means that more power can be generated – about 91 megawatts at full capacity. PG&E also built the original 22 megawatt power station at the old 1926 Melones Dam, under a 40 year contract with the Oakdale and South San Joaquin Irrigation Districts. While the power company would be allowed to market and earn revenue on the hydroelectricity produced, it had to pay royalties since the dam was owned by the irrigation districts. This model proved useful for financing irrigation projects on the Stanislaus River; hydropower sales contributed greatly to repaying the bonds issued for construction. An added benefit was that the Donnells and Beardsley dams regulate water flow down the Middle Fork, allowing more consistent power generation at the older Stanislaus Powerhouse. The last major hydroelectric project to be built on the Stanislaus River was the North Fork project, officially known as the North Fork Stanislaus River Hydroelectric Development Project. It was built by a partnership between the Calaveras County Water District and the Northern California Power Agency for both hydropower and domestic water supply. Although proposed since the 1950s, the project was not built until the late 1980s. The primary features include the New Spicer Meadow Reservoir completed in 1989, the McKays Point diversion dam and tunnel on the North Fork, and the Collierville Powerhouse located near Hathaway Pines and the older Stanislaus Powerhouse. Water falls from a height of 2270 feet (692 m) – more than at any other power station in the Stanislaus River system – to the powerhouse, where it generates up to 253 megawatts. In 2004, PG&E's license for the Tri Dam project expired, and a new contract with the irrigation districts had to be negotiated. One of the conditions was to increase in stream flows in the portions of the Stanislaus River that were dried up by hydropower diversions. Similar conditions had been set during the relicensing of the Spring Gap Stanislaus project in 1997. The increased flows will benefit recreation along the Sierra portions of the Stanislaus River, including whitewater boating, and fishing for rainbow and brown trout. The irrigation districts now jointly own the hydro facilities as the Tri Dam Power Authority and sell power to PG&E under contract. Hydroelectric power plants in the Stanislaus River systemNameOwnerCapacity(MW)Annual generation(MWh, 2001–2015)StreamAngelsUPA1.45,308OtherBeardsleyOID/SSJID11.044,635Middle ForkColliervilleCCWD/NCPA253.0431,822North ForkDonnellsOID/SSJID72.0248,562Middle ForkFrankenheimerSSJID5.014,364OtherMurphysUPA3.613,441OtherNew MelonesUSBR300.0417,880MainstemPhoenixPG&E2.09,357South ForkSand BarOID/SSJID16.269,481Middle ForkSpicer MeadowCCWD/NCPA6.016,213North ForkSpring GapPG&E7.033,744South ForkStanislausPG&E91.0334,251Middle ForkTullochOID/SSJID17.198,504MainstemWoodwardSSJID2.84,946OtherTotal788.11,740,457 Source:

The upper Stanislaus River watershed is mostly forested, with mixed coniferous communities (ponderosa pine, white fir, Jeffrey pine, incense cedar and sugar pine) along the hills and ridges. Hardwood forests (California black oak, canyon live oak and blue oak) and gray pine are common along streams and canyon bottoms, and in the foothills other hardwoods such as chamise, manzanita and mountain mahogany are present. Riparian zones, which include white alder and willow, are rare due to limited space along the narrow, rocky streambeds. Although mostly taken over by agriculture today, the lower watershed once was home to grasslands, oak woodland, and chaparral, which are still extant in some foothill areas. Riparian zones have experienced further decline from development in the floodplain and extensive mining for sand and gravel. However, some large areas of riparian habitat do remain, such as around Caswell Memorial State Park. 57 mammal species, and more than 200 bird species in the Stanislaus River watershed. Large mammals such as mule deer, bighorn sheep and black bear are common in the Stanislaus National Forest, which encompasses the high elevations of the watershed. The Stanislaus River is habitat for aquatic furbearers including beaver, river otter, and mink, which were extensively trapped for their fur during the 19th century. At least 36 fish species are known to exist in the lower Stanislaus River, including both native species such as salmon, steelhead/rainbow trout, Pacific lamprey, hardhead and Sacramento pikeminnow as well as introduced species such as carp, sunfish and bass.

The Stanislaus River provides habitat for native anadromous fish, particularly Chinook (king) salmon, and steelhead, which spend their adult lives in the ocean but must return to fresh water to spawn. In its natural state the Stanislaus had a major spawning run in the late spring (April–June) and smaller runs in the fall and winter. The construction of Goodwin Dam in 1913 blocked migration to about half of the available spawning habitat in the Stanislaus River basin, and populations have declined thereafter, especially since the construction of the Melones and Tri Dam projects which changed the flow pattern in the Stanislaus River. Between 1952 and 2015, the fall chinook population has ranged from a high of 35,000 in 1953 to zero in 1977. The average fall chinook number in the 21st century has been 3,558 fish. Water diversions have historically been considered the major factor decreasing salmon and steelhead populations. Before the construction of New Melones Dam, the river frequently ran dry starting in early summer, especially in drought years, due to farmers taking all the water. This prevented spring run smolt from making their way down to the sea. The little water left was usually too warm for the fish to survive. In 1992, federal dam operators began releasing large volumes of water or "pulse flows" into the Stanislaus River during the critical spring and fall spawning seasons hoping to replicate natural conditions of snowmelt and autumn storms, respectively, in order to help the fish reproduce. Between 2000 and 2009, about 55 percent of the Stanislaus River unimpaired flow was released from Goodwin Dam into the lower river, far more than the historical average of 39 percent. This is also considerably more than flows released into the nearby Tuolumne and Merced Rivers, which are also historical salmon and steelhead habitat. Because fishery flows compete with irrigation needs for water, the program has been unpopular with local farmers and water districts, as well as recreation dependent on Stanislaus reservoirs. Also, despite the pulse flows, salmon and steelhead have continued to decline from the late 20th century into the 21st century (with occasional resurgences in flood years).

On April 8, 2015, after four years of severe drought, the Bureau of Reclamation began releasing water from New Melones for fish, ignoring protest from farmers. Irrigation district managers ordered the gates closed at Tulloch Dam to prevent the water from flowing downstream. After a brief standoff lasting several hours, the Bureau of Reclamation stopped the flow. The districts objected because releasing water in the spring would cut drastically into their supply, as state regulations require that a certain volume of water be retained in New Melones for fall fish releases. Due to the drought, New Melones Lake was already at a low level, and there was not enough water to meet the farmers' demands in addition to the spring and fall releases. Ultimately, a temporary compromise was reached, allowing the lake to be drawn down to a lower level than environmental restrictions typically allow. This met the districts' demands for the year but also resulted in higher water temperatures. The effect of higher flows on anadromous fish has been difficult to quantify, in part due to the myriad of other factors such as pollution and non native predators. A 2009 biological opinion from the National Marine Fisheries Service suggested that even higher flows would be required for the fish populations to truly benefit. In 2017, the independent environmental consulting group FISHBIO released a study showing that the number of outmigrating fish may not be as strongly related to artificial pulse flows as previously thought. Data from the 2005–2016 period indicated that fish migration responded the same way to river flows of as they did to the required flows of
The California Department of Water Resources has continued to push for higher flows in the Stanislaus, Tuolumne, Merced and San Joaquin Rivers with the specific focus on volume of water released during spring runoff. Although over the course of the year, over half of the Stanislaus River's runoff is allowed to flow unimpaired down the river, this proportion is much lower – 20 percent or less – during the spring snowmelt when the majority of water is being captured in reservoirs for later use. The state has recommended that 40 percent of the spring runoff be allowed to flow down the river; some environmental groups have pushed for as much as 60 percent. These amounts would be greater than what is already required, leaving even less to support the local farming economy. The South San Joaquin Irrigation District – which, under the proposal, stands to lose as much as two thirds of its surface water supply during dry years – has pushed for all factors and potential solutions to be considered, including "better timing of releases, habitat restoration, hatchery management, addressing predators, water temperatures, more restrained water releases, and cool water pools behind reservoirs". Due to the Stanislaus River's limited flow, it has become clear that not all the demands on the river can be fully satisfied, forcing federal, state and local water managers to compromise. An interim program started in 2016 allows the Stanislaus irrigation districts to sell some river water to the San Luis & Delta Mendota Water Authority, which represents federal contractors in the southern San Joaquin Valley, at premium prices.

The Stanislaus River was California's first popular whitewater river; in the 1970s many commercial outfitters operated on the river between Camp Nine and Parrott's Ferry Bridge. Images and documents of rafting during this time can be found at the Stanislaus River Archive. Although this section was flooded by New Melones Lake in 1983, rafting and kayaking remain popular on sections of the Middle Fork and North Fork, as well as the main stem below Goodwin Dam. In addition, the Camp Nine run reappears when New Melones Lake is low, allowing boaters to run this part of the river, although siltation of the river bed due to reservoir impoundment makes access difficult. As of 2016, the Bureau of Reclamation is considering allowing commercial outfits to operate on the Camp Nine run once more, "whenever river flows and water levels in Melones Reservoir make it possible". The North Fork is the highest elevation commercially run river in California, and is also considered one of the most difficult runs in the state with thirteen rapids at Class IV or above. The best flows are typically limited to a six week window in April and May. During the summer, flows are regulated by New Spicer Meadow Reservoir, which most often releases water at night to generate hydropower. The Forest Service recommends taking a guided trip "due to the demanding and technical nature of the river", although private trips are also permitted. The Goodwin to Knight's Ferry run, though at a gentler gradient than the North Fork, also offers Class IV V rapids. Below Knights Ferry the Stanislaus becomes wider and smoother, with Class I II rapids between there and Orange Blossom Park; further downstream many parts of the river are suitable for flat water boating and swimming. The Middle Fork has the largest flow, but is subject to numerous hydro power diversions that often dewater the river bed in summer. The Sand Bar and Mt. Knight runs (14 mile (23 km) in total), rated "difficult" at Class IV–V+ are dependent on releases from Sand Bar Dam, which only occur when river flow exceeds the capacity of Stanislaus Powerhouse. The average season for this run is only about 3 weeks long, typically in early June. Due to the increasing popularity of whitewater boating, PG&E has been considering making higher dam releases during the summer.

About of the upper Stanislaus basin is within the Stanislaus National Forest, which provides a wide range of outdoor recreation including fishing, camping, backpacking, horseback riding, mountain biking and snowmobiling. The upper Stanislaus also includes parts of two major wilderness areas. The Carson Iceberg Wilderness is located along the North Fork and Clark Fork (the name "Iceberg" comes from a distinctive granite formation along the Clark Fork). The Emigrant Wilderness, encompassing , encompasses the upper Middle Fork and also borders on Yosemite National Park a short distance to the south. Boating, water skiing and camping are also popular on the many reservoirs along the Stanislaus River. The largest, New Melones Lake, is visited by up to 800,000 people per year and includes a full service marina providing boat rentals and supplies. The New Spicer Meadow Reservoir (the largest of the Stanislaus' high Sierra lakes) and Beardsley Reservoir both include camping facilities and boat ramps managed by the Forest Service. Donnell Lake is also open to the public, but due to difficult access and rugged terrain, it is much less crowded. Along the lower Stanislaus River, most of the land is privately owned. However, there are sixteen public access points in the 60 mile (97 km) stretch between New Melones Dam and the San Joaquin River. Other parks along the lower Stanislaus include Horseshoe, Orange Blossom, and Jacob Meyers Parks and the Oakdale and McHenry Recreation Areas, which include riverside trails, campgrounds, and access for boating and fishing. Caswell Memorial State Park covers along the lower Stanislaus River and is home to one of the last native riparian oak woodlands in the Central Valley.