Precommerical thinning in ponderosa pine stands in the Western United States is a growing practice. Thinning slash can, however, be a serious fire hazard in dry areas. Crushing and compacting this slash may be one way of reducing the hazard. Three types of mechanical crushers were tested on the Deschutes National Forest, Oregon. Results indicate that at least one of these methods of mechanical crushing is effecitve for lessening the fire hazard in thinning slash, and can be done at reasonable costs.