This longest undammed river in the U.S. on the Yellowstone River is the LeHardy's Rapids where you may be able to see the cutthroat trout leaping upstream in the Spring (early May through mid-July.) If you want to fish in this area, you'll need a fishing permit; however, state-issued fishing permits are not valid within the park. Passes are available at visitor centers, ranger stations, general stores, and other locations outside of the park. This excellent section of the Yellowstone River can be an exciting experience but keep in mind that when the salmon are spawning, this area could be closed off due to bear activity. LeHardy's Rapids Grand Loop is an excellent place to walk the boardwalk and observe the rapids. This trail extends from the path in two routes. Take the northern direction to a more forestry area into an overflow parking area or some small pebble-covered beaches. The location for this area is north of Fishing Bridge along the Grand Loop tour. Due to uneven ground and stairs on the southern part of the boardwalk, visitors with wheelchairs may require assistance.