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Genetic markers (genotypes) were recently associated with indices of terrain use (phenotypes) in grazing beef cattle. These indices were based on the ratio of a cow's average terrain use and average slope, elevation and horizontal distance to water of its contemporary group (cattle in the same pasture during the same time period). Ratios weighted the impact each metric of terrain use (slope, elevation or distance to water) equally even if a metric would not be expected to affect grazing distribution. Although ratio-based indices worked well, ratios are not effective metrics for calculating breeding values needed for genetic selection. Estimated progeny differences (EPD; a common method of comparing bulls during selection) use metrics with measureable units while ratios are dimensionless. Using published research, we estimated the time cows would graze a location based on slope and horizontal and vertical distance from water. The new index is the time cows spend in areas they are not expected to graze. Preliminary evaluations indicate that the developed indices can be used to compare terrain use of cows in different locations. In rolling terrain, developed indices were highly correlated (r > 0.8) to ratio-based terrain indices, but in mountainous terrain developed indices were moderately correlated (r = 0.3 to 0.4) to ratio-based terrain indices. Prior research may have underestimated grazing use of areas that are far horizontally and vertically from water at some ranches. Potentially we can adjust published relationships between forage utilization and terrain attributes using GPS tracking data and improve accuracy. Another obstacle in development of these indices is assigning the relative importance of slope and horizontal and vertical distance to water to the indices. In summary, indices that are direct numeric estimates of the traits appear to be more effective than ratios in predicting grazing use of beef cows in mountainous terrain.