The Lewis River is an 18.1-mile tributary of the Snake River flowing entirely within Yellowstone National Park in Wyoming. Beginning at the southern end of Shoshone Lake, the river flows southerly approximately 3 miles to Lewis Lake before reemerging at the southern end of the lake and continuing in a general southerly direction through a steep canyon. The river roughly parallels the South Entrance Road before merging with the Snake River shortly before leaving the park. Though not a major fishing destination compared to other Yellowstone fisheries, the Lewis River offers diverse fishing opportunities with several distinct sections, each providing unique angling experiences. The river takes a dramatic 29-foot drop at Lewis Falls, the most famous of many waterfalls and rapids along this scenic waterway.