Maps are updated approximately the first week of the month as follows: Surface Water Supply Index (Jan. - Oct.), Snow Water Equivalent (Dec. - June), Precipitation (year round), Streamflow Forecast (March – June), Reservoir Levels (year round).
View statewide maps of Surface Water Supply Index, Snow Water Equivalent, Precipitation, Streamflow Forecast, and Reservoir Levels
View individual basin maps of Streamflow Forecasts, Snow Water Equivalent, Precipitation, and Reservoir Levels
View pre-2016 Snow and Water Supply Maps
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These maps are produced in partnership with the NRCS. Data are compiled by the Montana Snow Survey Program of the USDA Natural Resources Conservation Service. Please see the NRCS web site for explanations of their data collection programs. For additional information, contact: Lucas Zukiewicz, Hydrologist Natural Resources Conservation Service Lucas.Zukiewicz@mt.usda.gov (406) 587-6843
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