The Upper Truckee River is 21.4 miles long and meanders through Alpine and El Dorado County. Its headwaters begin in Meiss Meadows and it flows through the town of South Lake Tahoe where it drains into Lake Tahoe.
The Upper Truckee River occupies 18% of the total watershed for Lake Tahoe, making it the largest input of fresh water to Tahoe.
Currently, there are wild populations of brook, rainbow and brown trout in the lower part of the river. The Lahontan cutthroat trout have been reintroduced above a natural barrier in Meiss Meadows and have established a self-sustaining fluvial population.