Physical fuel properties were determined utilizing measurements of volume, surface area, and weight for ponderosa pine forest floors and cheatgrass. Average values of these properties for ponderosa pine needle litter and cheatgrass were respectively: surface area-to-volume ratio (a), 57.6 and 144.0 cm.3/cc.; particle density, 0.51 and 0.34 g./cc.; loading, 324 and 53 g. /m.s; void volume-to-surface area ratio (A), 0.8 and l2.5 cc./cm.2; average particle spacing, 0.66 and 1.70 cm.; bulk density, 0. 0l6 and 0. 00032 g. /cc.; and (aX), 37.5 and 1810. Also presented are volume and surface area proportions of the forest floor litter and of the cheatgrass. A goodness-of-fit test showed that pine needles were randomly oriented in the horizontal plane and that cheatgrass particles were nonrandomly oriented in the vertical plane. Correlation analysis indicated that bulk density and particle spacing could be substituted for X, a fairly difficult variable to measure.