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Herbicides, commonly imazapic, are widely used for cheatgrass (Bromus tectorum) control on western U.S. rangelands.� Interception by shrub canopies may reduce the amount of herbicide reaching the soil surface or target species. The objective of this research is to compare the efficacy of a granular formulation of imazapic (Open Range G) to the widely-used liquid formulation (Plateau) for cheatgrass control beneath existing shrub canopies. We aerially applied both formulations of imazapic at 123 g ai�ha-1 for the liquid formulation and at 135 g ai�ha-1 for the granular formulation at two field sites (Saratoga and Pinedale, Wyoming) in 2015 with an untreated check at each site. In 2016, we collected cheatgrass biomass beneath shrub canopies and within interspaces between shrubs at both sites. No differences were detected between cheatgrass biomass beneath shrubs or in interspaces one year post-treatment at Saratoga (p=0.68) or Pinedale (p=0.78). Herbicide treatment was the only factor affecting cheatgrass biomass at Saratoga (p<0.0001) and Pinedale (p=0.0483). At Saratoga, both imazapic formulations provided similar reductions in cheatgrass biomass compared to the check, but at Pinedale, the liquid formulation reduced cheatgrass biomass more than the granular. To directly quantify herbicide reaching the soil surface, we used water sensitive paper for liquid imazapic and 2.37 liter buckets for granular imazapic to determine coverage of each formulation at two additional field sites (Hyattville and Sheridan) during aerial herbicide applications in 2016. Liquid imazapic coverage (%) was significantly greater in interspaces than under shrubs at Hyattville (p<0.0001) and Sheridan (p=0.0005). Granular imazapic weight (g ha-1) was not different under shrubs or within interspaces at both Hyattville (p=0.77) and Sheridan (p=0.72). Due to differences in application equipment and sites, cheatgrass biomass will be sampled under shrubs and within interspaces at all four field sites in 2017 to determine if similar results are achieved.