Mountain glaciers are closely coupled to climate processes, ecosystems, and regional water resources. To enhance physical understanding of these connections, the USGS maintains a collection of glacier mass balance and climate data across the western United States and Alaska. In some cases, records of glacier mass balance extend back to the mid-1940s. These data have been incorporated from various sources, primarily original USGS studies, but also including work from the University of Alaska, and the Juneau Icefield Research Program (JIRP). The core of this collection is composed of mass balance data from the USGS Benchmark Glaciers. These five glaciers are Lemon Creek Glacier, AK (1953 -Present), South Cascade Glacier, WA (1958 - Present), Gulkana and Wolverine glaciers, AK (1966 - Present), and Sperry Glacier, MT (2005 - Present). Datasets from each benchmark glacier are composed of, at a minimum, point mass balances, glacier hypsometry, daily temperature and precipitation, geodetic mass balances, and glacier-wide mass balances. Data from other glaciers within this collection may be less complete, continuous, or representative as data from the benchmark glaciers. In these cases, we urge users to carefully inspect the associated metadata of each specific data release for further details.