USDA Forest Service

Pacific Southwest Research Station


Pacific Southwest Research Station
800 Buchanan Street
Albany, CA 94710-0011

(510) 559-6300

United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Evaluating Effects of Ski Resorts on the American Marten

This study will evaluate whether recreational activities at ski resorts have significant effects on populations of the American marten (Martes americana). The marten is a carnivorous mammal that is designated as a "sensitive" species by the Forest Service and a "species of special concern" by the California Deprtment of Fish and Game.

Marten photo by Annie Mazzoni
Marten photo by Annie Mazzoni

Full Title: The effects of ski resorts in the Lake Tahoe region of California on population dynamics of the American marten

Proposal [pdf]

Lead Researchers: Keith M. Slauson and William J. Zielinski, USFS Pacific Southwest Research Station

Objectives: The project seeks to answer whether ski resorts have a net negative, neutral, or positive effect on marten populations in the Lake Tahoe region by comparing differences between ski areas and control areas in terms of:

  1. Loss and fragmentation of suitable habitat
  2. Marten density
  3. Marten seasonal movements
  4. Marten age structure and sex ratio
  5. Proportion of female martens that reproduce
  6. Marten population stability

Sites: (see figure)Martin Study Areas


  • Three treatment areas (Heavenly, Sierra at Tahoe, and Alpine/Homewood ski resorts) paired with control areas (non ski resorts) matched with respect to the overall amount, composition, and suitability of marten habitat as well as major topographic characteristics

Timeframe: October 2008 through December 2011 (3 years)

Expected date of final products: December 2011.
Progress Report available for download


  1. Quarterly progress updates and annual progress reports
  2. Final report prepared at the conclusion of the study
  3. Presentation of research findings in public and scientific meetings in the Lake Tahoe Region and elsewhere
  4. Paper(s) for publication in scientific journals
Last Modified: Mar 28, 2013 02:52:07 PM