Density estimates of four mammal species in the upper subalpine and alpine zones of the Sierra Nevada range, 2008 - 2012. The estimates were derived from variable distance data collected 3-4 per year along each of 21 transects (10 km in length). The transects were randomly selected from a pool of 53 potential routes. Nine transects were sampled in 2008, 12 were sampled in 2009, 19 were sampled in 2010, 21 were sampled in 2011, and 17 were sampled in 2012. All counts were done in July and August each year. Replicate samples within a given year were done within 2-8 days of each other. All counts were done by single observers. The spreadsheet has six worksheets, including three with density estimates for each species at different scales, one worksheet with definitions of the fields, one worksheet with the species names, and a worksheet that defines the scale and units of the estimates in the five worksheets for density