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water front

Tri-Dam Project is a partnership between the Oakdale Irrigation District and the South San Joaquin Irrigation District. Together they developed, operate and maintain the Beardsley, Donnells and Tulloch projects including the dams, tunnels, penstocks, powerhouses, communications systems, and general offices. These facilities are located on the Middle Fork of the Stanislaus River in Tuolumne County, California.

The “Upper Works” include Donnells and Beardsley dams, reservoirs, powerhouses and appurtenant facilities. The “Lower Works” refer to the Tulloch development below Jamestown reaching into both Calaveras and Tuolumne Counties.


Reservoirs operated by the Tri-Dam Project offer many opportunities for recreation. Two of our three reservoirs (Donnells and Beardsley) are in the Summit Mi-Wok Ranger District of the Stanislaus National Forest, in the beautiful high country of the Central Sierras.

Donnells Reservoir

May contain: outdoors, water, nature, and mountain

Donnells is situated in the Stanislaus National Forest on the Middle Fork of the Stanislaus River between Clark’s Fork and Beardsley Reservoir. Vehicle access to Donnells Reservoir is over a US Forest Service road when the road is open to the public. The dirt road is 9 miles long from its junction with the Beardsley Road to the dam site. The road is subject to US Forest Service closure from November 1 to April 15. There are no visitor facilities at Donnells Reservoir. There are no developed camping areas, toilets, or potable water.

The 8 mile stretch of river between the Donnells Dam and the upper end of Beardsley lies in a deep canyon with a few unmarked access points and is difficult to traverse.

The best view of Donnells Reservoir is from the Donnells Overlook about 15 miles east of Strawberry on Highway 108. The US Forest Service developed site has ample parking, chemical toilets, expanded accessible paved trails, interpretative signs, and an overlook platform with an expansive view of the Reservoir. There is neither potable water nor camping at this site. We invite everyone to visit this newly improved majestic overlook.

For additional information about recreation near Donnells visit the US Forest Service website.

Beardsley Reservoir

The Black Oak Flat Campground, located approximately 5 miles from Highway 108 on Beardsley Rd. provides 18 campsites, water and restrooms. There are also developed campsites at Beardsley Reservoir, located at the end of paved Beardsley Road off of Highway 108 about 5 miles east of Strawberry and about 5 miles down the canyon. The Beardsley Day Use and China Flat Day Use areas have accessible restrooms and provide additional picnicking, wildlife viewing, fishing and swimming opportunities. There are both day use facilities and limited overnight facilities. More information about recreational opportunities in the area surrounding Beardsley may be found at the US Forest Service website.

Both Donnells Reservoir and Beardsley Reservoir are located within the Stanislaus National Forest, within the Summit Ranger District: #1 Pinecrest Lake Road, Pinecrest, CA 95364; (209) 965-3434.

Tulloch Reservoir

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Tulloch Reservoir is situated on mostly private lands with substantial residential development on the Calaveras County portion of its shoreline. Access to the Reservoir is from privately owned docks and through privately owned facilities accessible to the public on a fee basis. Access to the South Shore is via Tulloch Dam Road off of Highway 108 and to the North Shore via O’Byrne’s Ferry Road also off of Highway 108.