Three Rivers PeakThree Rivers Peak is a mountain summit in the southern section of the Gallatin Range in Yellowstone National Park, in the U.S. state of Wyoming.ClimateAccording to the Köppen climate classification system, it is located in a subarctic climate zone with long, cold, snowy winters, and cool to warm summers. Winter temperatures can drop below −10 °F with wind chill factors below −30 °F.