This note presents equations for calculating maximum spot fire distance from firebrand sources in the Intermountain West based on prevailing windspeed, vegetation cover, and terrain in the area. The equations include the capability to predict spotting distance from a torching tree(s) or from a continuous flame source such as slash piles or jackpots of heavy fuels. The equations can be used on a programmable pocket calculator. Potential uses are seen in fire management planning and real-time fire behavior predictions. For copies of a program for the Texas Instruments TI-59, send seven blank TI-59 magnetic cards to the author.