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Wyoming big sagebrush (Artemisia tridentata wyomingensis) has been historically treated through chemical application, mechanical treatments, and prescribed burning to increase the amount and quality of herbaceous forage available to wildlife and livestock. Treatments are often intended to rejuvenate sagebrush stands by killing older sagebrush plants to promote growth of younger sagebrush plants and increase resources for herbaceous production. We evaluated the vegetation response of mowing and herbicide treatments in Wyoming big sagebrush habitats in central Wyoming as part of a larger study to evaluate how sagebrush treatments influence habitat selection and demographic parameters of greater sage-grouse (Centrocercus urophasianus). Mowing and Spike� 20P treatments were applied in the winter and spring of 2014, respectively. We installed exclosures to exclude livestock from treated and paired untreated sagebrush. Shrub characteristics, grass height, herbaceous canopy cover, and ground cover were evaluated at treated and untreated sagebrush in 24 exclosures that excluded livestock grazing and at 100 treated and untreated areas where livestock grazing occurred from 2014 to 2016. Vegetation characteristics were estimated along two perpendicular 30-m transects centered at each location and followed protocols similar to those used to evaluate sage-grouse microhabitat selection. As expected, treatments resulted in a reduction in sagebrush cover and height; however, herbaceous understory response was variable and often mimicked untreated reference locations in both grazed and un-grazed locations. Our results corroborate other studies that suggest treating Wyoming big sagebrush communities does not often result in short-term increases in herbaceous understory.