How do rivers in the northern plains have water even in summer?

Rivers in the northern plains often have water during the summer due to several factors, including snowmelt from the nearby mountains and glaciers, which provides a steady flow of water as temperatures rise. Additionally, groundwater contributions and rainfall during the spring and early summer months help maintain river levels. The geography of the plains, along with the drainage patterns of the region, also plays a crucial role in sustaining these waterways throughout the warmer months.