Water resources programs and activities of the U.S. Geological Survey in Montana consist principally of hydrologic data collection (6 projects); local areal, or statewide hydrologic investigation (12 projects); and research (1 project). The work is supported by direct Federal funding, by transfer of funds from other federal agencies, and by joint funding agreements with state or local agencies. The projects funded for fiscal yr 1986, the operations of the Montana District, water conditions during the preceding year, activities in addition to regular programs, sources of publications and information are described, and reports published or released during the preceding 5 yr are listed. (Author 's abstract)