Groundwater peak flows that trigger landslides in the northern Rocky Mountains occur in the winter and early spring when access is limited. The Forest Service, US Department of Agriculture, is developing instrumentation for monitoring groundwater under these conditions. The system operates unattended under extreme weather conditions for 9 months, powered by rechargeable batteries I stores groundwater data on solidstate integrated-circuit storage modules that can be read directly into a host computer for data processing I is adaptable to precipitation monitoring, and is relatively inexpensive. Instrumentation and installation problems, as well as remedial measures, are discussed. Sample field data recovered since 1981 and practical applications of that data, including groundwater rise in response to precipitation modeling, landslide correction, and aquifer analysis, are discussed.