Ask the Wyoming Game and Fish
Q. I like to fish streams with worms and salmon eggs, but it seems most are restricted to artificial lures and flies. Why is that?
A. First off, there are more streams where bait is legal, than otherwise. If bait is not legal on a particular water, that water will be listed in the fishing regulations booklet in the Regulations Exception sections for each drainage area. If the stream you want to fish is not listed as requiring artificial lures and flies, you may use your worms and eggs. Artificials are required on some waters for fisheries management purposes, usually to protect certain species or sizes of fish while still allowing fishing opportunity. Studies have shown that fish caught using bait have a much higher mortality than fish caught using artificials, hence the regulation.