The longest free-flowing river in the lower 48 states, the 670-mile (1,080-kilometer) long Yellowstone drains the national park into the Missouri River system. Originating in the Absaroka Mountain Range the river flows north through the park, flowing across the plains of Montana and North Dakota, meeting up with the Missouri River near Buford, North Dakota.

In Yellowstone National Park, its deep, colored canyon and high, misted waterfall are hallowed views.

The Yellowstone River is famous among anglers and fly-fishers as a world-class trout stream. The lack of dams provides excellent habitat for migrating trout. Fly fishing is a popular activity along the course of the river, and particularly popular in Yellowstone National Park itself. The park provides hundreds of miles of accessible streams and lakes for fishing.

Year-round.

Fees: Check state laws for license fees.