Level of Concern:


Prosopium williamsoni

Mountain whitefish persist in some fragmented water bodies in California, but their overall abundance and distribution are reduced from historical levels and may be continuing to decline. Population estimates and comprehensive distribution surveys are lacking; while their overall status remains uncertain, it appears to have declined.

How we're working to save them:

Conservation Actions

  • Conduct a population study to determine distribution and abundance of Mountain whitefish.
  • Include Mountain whitefish in CDFW management and restoration currently focused on other salmonids that overlap their range, such as Lahontan Cutthroat trout.
  • Consider reducing current daily bag limits of 5 Mountain whitefish per angler/day until reliable abundance data are available.
  • Expand ongoing negotiations in the Tahoe, Carson, Walker, and Truckee basins that keep water in streams and enhance habitat for all native fishes.

Click here to learn about CalTrout’s overall “Return to Resilience” plan to save California’s salmonids from extinction.

Where to find Mountain Whitefish:

Mountain Whitefish Distribution

Mountain whitefish historically occupied similar habitats to Lahontan Cutthroat trout on both the California and Nevada sides of the Sierra Nevada. Their current range in California includes the Lower, Little, and Upper Truckee, East Fork Carson, and East and West Walker river drainages on the east side of the Sierra Nevada, and perhaps the West Fork Carson River as well. They can also be found in natural lakes, including Tahoe, Independence, Cascade, and Fallen Leaf lakes.

How the Coastal Rainbow Trout Scored:

From CalTrout's SOS II Report


Mountain whitefish are not trout, but rather a unique-looking relative of trout and grayling with an olive/dusky green back and large silver scales. They are one of the most widely distributed salmonids, but are not well studied in California. They have a downturned mouth that allows them to feed on the streambed, and a prominent adipose fin. In streams, they tend to be relatively small, usually less than 25cm (10 in.), but may reach up to about 35cm (14 in.) and 2kg (4.4 lbs.) in lakes.


Basic distribution and population data for Mountain whitefish are generally lacking, so their overall status in California remains uncertain. While still present in much of their limited range, their populations are disconnected and seemingly shrinking. The absence and low densities of Mountain whitefish observed over the last several years in surveys around Lake Tahoe may indicate that the status of this species has declined since 2008.

Habitat & Behavior

Mountain whitefish are capable of living to more than 10 years of age, depending on habitat and food availability. They frequently shoal in groups of 5 to 20 fish close to the bottom of streams and lakes. They tend to feed on benthic aquatic insects in deep, slow pools, especially at dawn or dusk, but will rise through the water column to opportunistically prey on drifting invertebrates. Their general feeding and holding patterns only slightly overlap with those of closely related trout. From October through December, Mountain whitefish return to natal streams to scatter their small, adhesive eggs over gravel.


The Lahontan Basin population (Nevada and California portions of the range) of Mountain whitefish in North America are distinct, due to geographic isolation from other populations, and may eventually deserve their own taxonomic designation.

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