George Fahnestock's work (1960) on logging slash was a guide for establishing the experimental plots. The purposes of his study and the present one were different. Fahnestock was interested chiefly in comparing the influences of species, loading, and aging on burning slash. He was evaluating factors that influence the burning of natural beds of logging slash. The study reported here was designed to relate flame front characteristics to a specific fuel bed. To facilitate the comparison of data from the two studies, fuel beds were loaded at the same weights per acre (7.5, 20.0, and 32.5 tons per acre) as Fahnestock had used. We used slash from lodgepole pine and Douglas-fir, two of the nine species that Fahnestock studied. Rather than using 20- by 20-foot plots with center firing as Fahnestock had, the 1962 plots were 6 by 60 feet and fired at one end to represent a moving segment of a fire front.