Sierra National Forest
Mammoth Pool Reservoir is located on the San Joaquin River and lies within both Madera and Fresno Counties. The lake, which is 90 miles northeast of Fresno, is about 5 miles long and up to 1/2 mile wide. The reservoir provides recreational activities from mid-June until the main road is closed in late fall because of winter weather.
The lake is formed behind a dam, which is operated by Southern California Edison Company to produce hydroelectric power. Maximum storage capacity is 120,000 acre-feet.
Surface acreage is 1,107 acres at an elevation of 3,330 feet. It was named after a large, natural pool in the river just above the location of the dam.
The mountains that surround the reservoir form a steep narrow valley and rise 2,000 feet above the lake's surface. Ponderosa pine and incense cedar are intermingled with live and black oak and chaparral at the lower edge of the Transition Life Zone. A careful observer may see gray squirrels, California mule deer, raccoons, coyotes and other wildlife.
Mammoth Pool is closed to the public from May 1 until June 16. Fishing is prohibited in the lake and 300 feet above the high water mark in all tributaries. Roads accessing Mammoth Pool are closed at Mammoth Pool Campground and the Chiquito Creek Bridge.
Mammoth Pool is a very good fishery. Rainbow, eastern brook, and German brown trout are found in the reservoir. Fishing season extends from near mid-April to late fall when the access road is normally closed because of winter storms. However, California State Fish and Game Department regulations prohibit fishing on the reservoir waters from May 1st until June 16th. This is to allow migrating deer to swim across the reservoir.
Mammoth Pool has a boat launch for larger boats. Before you head out, pick up a copy of the regulations; the lake has stringent speed limits and other regulations.
Though there are no designated swimming beaches, there are opportunities for swimming near flat shorelines. Caution should be exercised since the cold water temperature will reduce a swimmer's endurance. No lifeguard service is provided.
The French Trail runs on the west side of the reservoir, and may be accessed at the Logan Meadow or Shakeflat trailheads. The trail was surveyed in 1880 and built by John S French, a mining promoter from San Francisco who was developing mines in the Mammoth Mountain area. He needed a trail to reach his mines so he built the trail starting at Ross's Ranch and ending due south of Devil's Postpile. In the vicinity of Mammoth Pool, the trail runs through mixed conifer forest and rocky, brush-covered hillsides. It is best hiking in the spring or fall, since it is quite hot during the summer.
Mile High Vista point offers a spectacular view of Chiquito Basin, pans of the Ansel Adams Wilderness and the upper reaches of the San Joaquin River. With binoculars, one can see the upper lift ski tower on Mammoth Mountain on the east side of the Sierra Nevada.
Seven Forest Service and one privately-owned campground are located within 13 miles of Mammoth Pool. The Wagners Resort store offers food, gas and fishing supplies.
The Forest Service campgrounds have a total of 98 camp units. Mammoth Pool Campground, with 47 units, has piped in water. Other campgrounds do not have water. China Bar Campground is primitive and is accessible by boat and via the French Trail.
Details mentioned in this article were accurate at the time of publication