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Invasive species have ever-increasing impacts on ecological and economic functions of ecosystems. Cheatgrass (Bromus tectorum L.) is an invasive annual grass that is widely distributed throughout most of the western United States. Cheatgrass produces high amounts of fine fuels which can increase fire frequency and severity, altering vegetation composition and structure. Although cheatgrass can be used as early spring forage by livestock and wildlife, it may not be preferred, so its suitability as a forage species is questionable. We hypothesize that there is a direct, predictable relationship between pre-treatment vegetation condition and post-treatment forage response that may be defined at lower levels of cheatgrass by minimal post-treatment grass response and in more severe infestations by more pronounced increase in perennial forage following treatment. By identifying these treatment-response thresholds, we hope to aid land managers in prioritizing where their treatments will provide a high level of benefit. In summer 2015, we sampled locations representing a gradient of cheatgrass to perennial grass biomass and canopy cover ratios prior to herbicide application across multiple sites. At each intensively sampled location we employed four different sampling methods to determine the ratio of cheatgrass to perennial grass using both biomass and cover measurements. Comparisons will be made among sampling methods to determine if each method yields similar results in perennial grass response to herbicide treatment. We aerially applied two imazapic formulations during fall 2015. Post-treatment data will be collected in 2016 to evaluate the response of cheatgrass and associated vegetation following herbicide application for cheatgrass control. With a better understanding of cheatgrass and perennial grass response following herbicide treatment and various cheatgrass infestation thresholds within an ecosystem, we aim to provide valuable information which land managers can use to refine landscape-scale management strategies.