Upper Missouri Waterkeeper


Guy Alsentzer
[email protected]
(406) 570-2202

From the Missouri’s utmost source that tributary river flows 298 miles through mountain valleys of southwestern Montana. Along the way it merges with numerous headwater rivers: the Red Rock River, the Beaverhead, the Big Hole and then the Jefferson, where it arrives in Three Forks and Headwaters State Park. There, it finally merges with the Madison and the Gallatin, the “official” start of the Missouri River. Fittingly, the breadth of these three primary riversheds is called the Missouri Headwaters subbasin.

Guy approaches the work of safeguarding water resources as an attorney, farmer, and outdoorsman. Raised on a family farm, Guy has an unquenchable thirst for unique landscapes and all things water. His family passed on their passion for sustainable, local farming alongside lifetime hobbies like sailing, swimming, fishing and boating. Prior to founding Upper Missouri Waterkeeper, Inc. Guy served for nigh 3 years as Staff Attorney and Director of Operations for Lower Susquehanna Riverkeeper. He also helped manage his family’s farm in rural Pennsylvania. Guy has built campaigns challenging illegal pollution discharges, LNG export terminals and shale gas fracking, as well as worked on the relicensing of major hydroelectric facilities, fisheries and imperiled species management issues, and the workings of interstate water compact agencies. He previously earned his spurs working at Vermont Law School’s Env’tl and Nat’l Resources Law Clinic, the Gallatin County Attorneys Office in Bozeman, and Western Environmental Law Center’s Northern Rockies Office in Helena. Guy lives in Bozeman where he enjoys kayaking and climbing in the Gallatin, fishing the Big Hole, hunting Montana’s wildlands and skiing the Cold Smoke, though not at the same time. He also serves on the City of Bozeman’s Wetlands Review Board where he puts to action his belief in citizen engagement with local government. Guy holds a B.A. in Political Science from Pepperdine University, an M.S. in Environmental Law & Policy and a J.D. from Vermont Law School, and is a member in good standing with the State Bar of Montana.


24 S Wilson Ave Ste 6-7
Bozeman, Montana 59715