Intermountain GIS Conference

A trend of increasing wildfire frequency has necessitated the development of methods toidentify forested areas with heightened fire susceptibility. One specific concern in forested areas is susceptibility to canopy fires due to the presence of ladder fuels. Fuel reductiontreatments that target areas where ladder fuels are present are effective at mitigating canopy fires, but it is difficult to identify where ladder fuels exist within large forests. Past studies have demonstrated lidar (Light Detection and Ranging) technology can be used to detect the presence of ladder fuels. This study began with a literature review investigating current lidar applications for ladder fuel identification and subsequently led to the development of a model that quantifies ladder fuel density in forested areas. The model output is a raster image that can be used by land managers to help prioritize fuel load/ladder fuel reduction treatments. The accuracy of the model was field validated in the summer of 2025, demonstrating sites with predicted low estimated ladder fuel density (20%) do indeed exhibit low ladder fuel abundance in the field. Likewise, sites predicted as having high estimated ladder fuel density (66%) exhibited high ladder fuel abundance in the field.

This study investigated trends in aspen (Populus tremuloides) extent and distribution in southeast Idaho to inform targeted management decisions for Bureau of Land Management (BLM) project partners seeking to promote aspen stand health. Remotely sensed Landsat imagery combined with aerial imagery, topographic layers, and in situ observations were used to train a probabilistic decision forest model to model aspen at three scales: 1) a focused study area (FSA) scale, 2) a watershed basin scale, and 3) targeted regions of interest where active management has been conducted. Climatic datasets were used to interpret model results. Historic wildfire locations were used to better understand the study area’s disturbance regime. Model results suggest aspen has declined in extent across the FSA by approximately 50,000 acres (32%) between 2004 (163,356 acres) and 2025 (112,320 acres). Watershed basin analysis shows spatial variability with some basins exhibiting stable aspen extents while others show declines. Personal communications with land managers indicate the model overestimated aspen extent. Various interacting factors may be driving aspen decline including (1) lack of disturbance and infrequent fires affecting aspen in the northern section of the FSA, (2) rising Tmin, Tmax, growing degree days, and frost-free days causing prolonged periods of stress –especially during drought years-- leaving them susceptible to secondary disturbance factors like pests, pathogens, and increasing competition pressure with conifers. Even when considering model uncertainties, aspen are most likely experiencing a decline across eastern Idaho. Further research, monitoring, and management activities to promote aspen habitat is merited

Craters of the Moon National Monument and Preserve is a stark, challenging landscape that defends its beauty and wonder with rattlesnakes, razor-sharp rock, weather, and isolation. There are no roads. Horses cannot be used. Exploration and mapping of the vertical caves in the lavas requires long (sometimes multi-day) hikes over treacherous ground while carrying ridiculously heavy packs full of vertical gear, water, and camping equipment. Suffering is often a prerequisite for the desert to yield its secrets, and Edward Abbey may have said it best: "In the first place, you can't see anything from a car; you've got to get out of the goddamned contraption and walk, better yet crawl, on hands and knees, over the sandstone and through the thornbush and cactus. When traces of blood begin to mark your trail you'll begin to see something, maybe. Probably not."This presentation will focus on the exploration, mapping of caves, and efforts to expand Craters of the Moon National Monument during the 1990s. Cave-mapping techniques in the 90s were challenging, as conditions were dark, wet, cold, and frequently dangerous.  Mapping instruments consisted of a compass, clinometer, and tape measure. Drawing ability was necessary to sketch the cave on waterproof Mylar sheets. Data collection used the “LRUD” (Left, Right, Up, Down) method for measuring cross-sections, and maps were generated using early CAD software. In the late 1990s, laser technology and began to replace the tape measure.