Earth systems in the intermountain West are increasingly prone to disturbances from changes in climate, land management, and tree mortality due to fire and other factors. Mortality due to pine beetle infestations, for example, has reached record levels, with over 4 million hectares affected in the US, causing immediate, sweeping changes in mountain ecosystems. The annual area affected by bark beetle infestations in North America is comparable to that burned by fire, with hydrologic impacts of presumably similar magnitude. Human disturbance can also regulate hydrologic processes. For example, Wyoming is in the midst of an oil and gas development boom, with tens of thousands of wells emplaced over the past decade. Although hydrologic impacts of individual wells may be minor, the cumulative effects of thousands of acres of surface disturbance, emplacement of infrastructure, and discharge of produced water are altering hydrological systems throughout the state. Predicting impacts of these activities on water distribution will allow for productive and informative planning regionally and nationally. Finally, predicting hydrological responses to climate change depends in part on an accurate understanding of how watersheds have responded to such changes in the last 1000 – 10,000 years. Earlier snowmelt and reduced snowpack are likely effects, which will likely stress fish populations. The timing of glacier melt timing in Wyoming has been reported to be changing over the past two decades. Research is needed to reduce uncertainties about such observations to predict the allocation of water resources in coming decades.