Management practices have altered both the structure and function of forests throughout the United States. Some of the most dramatic changes have resulted from fire exclusion, especially in forests that historically experienced relatively frequent, low- to moderate-intensity fire regimes. In the Sierra Nevada, fire exclusion is believed to have resulted in widespread vegetation changes, including greater density and cover of white fir (Abies concolor) and reduction in the area occupied by hardwoods and shrubs (Parsons and DeBenedetti 1979, Vankat and Major 1978). Fire exclusion has allowed both live and dead woody fuels to accumulate, increasing the probability of large, high-severity, stand-replacing fires (Stephens 1998, van Wagtendonk 1985). The Fire and Fire Surrogate (FFS) study is a national research effort to evaluate the economics and ecological effects of alternative fuel reduction methods to reduce wildfire hazard. Funded by the Joint Fire Science Program, USDA Competitive Grants, and the National Fire Plan, the study consists of a network of 13 sites located in forested ecosystems across the country, each characterized by a historical regime of frequent low to moderate intensity fire. Two of these sites - Blodgett Forest Research Station and Sequoia National Park-are located in the Sierra Nevada. The consequences of four management options are being assessed at Blodgett Forest: mechanical treatment alone, prescribed fire alone, mechanical + prescribed fire, and untreated control. Treatments at the Sequoia National Park site are early season prescribed fire, late season prescribed fire, and untreated control. All sites in the network are collecting data on the same suite of variables, including overstory and understory vegetation, fuel and fire behavior, soils and the forest floor, wildlife, entomology, pathology, treatment costs, and utilization economics. Treatments at the Sequoia National Park site were completed in June of 2002, and all but the prescribed burns had been conducted at Blodgett Forest by October 2002. Post-treatment results from Blodgett Forest are only available for the period after thinning and prior to burning. The majority of post-treatment data collection at both sites will not occur until 2003 and 2004. Post-treatment data from both sites should be considered preliminary.