Mountains play a critical role in freshwater supply for downstream populations. As the climate changes, groundwater stored in mountain regions may help buffer impacts to mountain water resources due to declining snowpack and glacier recession. However, rising air temperatures in mountain regions will increase evapotranspiration and alter snow and ice melt timing and quantity, which may impact recharge rates and storage. Due to the limited accessibility of mountain regions, it remains unclear how mountain groundwater is being impacted by climate change. This research aims to quantify trends in mountain groundwater storage and improve our understanding of how various climatic, physiographic, and anthropogenic factors affect mountain groundwater vulnerability. To accomplish this, data was compiled from observation well networks across Canada and the United States. The resulting dataset contains 171 mountain wells with at least 20 years of continuous monthly data. The Mann-Kendall test for monotonic trend revealed that 54% of these wells have statistically significant trends (p < 0.05) over the period of record, of which 69% were negative (declining storage). Next, we applied correlation analysis and factor analysis to quantify variability in the dataset and to understand relationships between groundwater trends and characteristics of the groundwater system. Preliminary results show greater changes in groundwater trends throughout the Western Cordillera, particularly at lower latitudes where average annual temperatures are warmer. This research will expand our understanding of a critically important water resource beyond the local scale and provide important insights into the vulnerability of mountain groundwater under climate change.