A uniform layer of volcanic ash from the eruption of Mount Mazama ~7600 years ago once mantled the Palouse Range of northern Idaho. In many places this mantle has been disturbed by post depositional processes. Understanding the relationships of terrain variables and the post depositional distribution of this volcanic ash is important for forest soil management practices. Eighty-four research sites were visited across the Palouse Range. Soils were described using standard field sampling techniques and assessed for ash mantle presence/absence and depth.  All 84 samples were collected for further lab analysis which included NaF pH and acid ammonium oxalate extraction. Samples were evaluated using a mixing index that assesses the disturbance of volcanic ash mantles. Light Detection and Ranging (LiDAR) data was acquired for the Palouse Range of northern Idaho and a 1m high resolution digital elevation model (DEM) was generated. This DEM was resampled to 10, 15, 20, and 30m grid resolutions to evaluate scale influences. Landscape attributes were extracted using two data sets, one implemented a pit-filling process and the other skipped this process. For all data sets, exploratory data analyses and classification trees were generated from landscape attributes for presence/absence, thickness, and mixing of volcanic ash. Probability maps were generated using map algebra if-then statements for the ash mantle presence/absence data sets. An accuracy assessment using 587 NRCS data points was performed on the probability maps. The 30m grid resolution provided the best model with 78% accuracy. The various grid resolutions did not affect the outcome and predictability of the models, and the overall accuracy of the models varied by 2%. Comparison of the data sets showed that the pit-filling process did not diminish the power of the models to predict ash mantle presence/absence. Elevation is the single variable most related to presence/absence, mixing, and thickness of volcanic ash mantles. Elevation is strongly linked to climate and vegetative communities.  Moister, high elevation vegetative communities provide a protective forest canopy and organic matter layer, which leaves the ash mantle relatively undisturbed. At lower elevation where the forest canopy is less dense the ash mantle is thinner, highly mixed, or absent.