Yellowstone National Park Professional Review and Guide
"Although Yellowstone Park owes its world-fame to its spectacular geysers, abundant wildlife, and unique scenery, the park also offers exceptional angling opportunities. Over 160,000 anglers a year take advantage of its high quality fishing. Yellowstone is richly endowed with over a hundred superb trout streams and subalpine lakes. Despite the tremendous and ever-increasing pressure from anglers, fishing in the park has actually been improving over the past ten years. Regulations aimed at protecting the fishery and the complex food chain of this extraordinary ecosystem were extensively revised in 1970.
Today, Yellowstone Park has some of the most restrictive and successful regulations in the country. They include local and seasonal closures to protect spawning fish, the elimination of bait fishing, size and creel limits, catch-and-release for most of the park, and fly fishing only waters. The results have been more fish, a greater diversity of fishing opportunities, and more anglers taking advantage of these opportunities. The percentage of successful anglers has risen, and in many waters, average fish size is increasing."