Beaver in the Sierra Nevada

[1] The California Golden beaver subspecies (Castor canadensis subauratus) was prevalent in the Sacramento and San Joaquin River watersheds, including their tributaries in the Sierra Nevada.

In 1916, Harold Bryant wrote in California Fish and Game, "The beaver of our mountain districts has been entirely exterminated and there are but a few hundred survivors to be found along the Sacramento, Colorado and San Joaquin Rivers.

These native "Central Valley" beaver have been building dams and rearing young successfully for 70 years in and near Yosemite at elevations higher than 5,000 feet (1,500 m).

Castor canadensis were re-introduced to the Tahoe Basin by the CDFG and the U. S. Forest Service between 1934 and 1949 in order to prevent stream degradation and to promote wetland restoration.

[16] However, not only have aspen and cottonwood survived ongoing beaver colonization but a recent study of ten Tahoe streams utilizing aerial multispectral videography has shown that deciduous, thick herbaceous, and thin herbaceous vegetation are more highly concentrated near beaver dams, whereas coniferous trees are decreased.

[17] The presence of beaver dams has also been shown to either increase the number of fish, their size, or both, in a study of brook, rainbow and brown trout in Sagehen Creek, which flows into the Little Truckee River at an altitude of 5,800 feet (1,800 m).