From its headwaters near Walden, Colorado, the Upper North Platte is still a freestone river. Flows are determined by mother nature rather than man, but it generally fishes well March through October, weather pending.
The float season is determined by the amount of snow pack accumulated through out the winter and precipitation through out the summer. In a good year with above average snow pack and good precipitation through out the summer the float season will last all summer and into the fall. In a bad year the float season may only last a couple months.