The two major species of black bass, largemouth and smallmouth, are widely distributed across the United States, their original ranges having been greatly expanded by stocking programs.

They are popular with many fish stocking programs because they can grow quickly, and may help keep rough fish populations in check due to their highly piscivorous (fish-eating) nature.

Most of the resulting offspring are returned to the natal streams, but some are kept in hatcheries and reared to adulthood to produce more young fish for stocking programs.

Several states, including Missouri, have enacted stocking programs for these fish in reservoirs where the resident populations were low or nonexistent, or in areas where historical populations are no longer naturally sustainable.

This makes tigers popular with many fish stocking programs, such as with the Utah Division of Wildlife Resources.

The state's turkeys are doing so well that many have been trapped and used for stocking programs in other states and countries, including Vermont, Connecticut, New Hampshire, Maine, Massachusetts, Minnesota, New Jersey, Rhode Island and Delaware.

In 1955 all stocking programs in the park were discontinued and today's Firehole trout are completely wild populations.

Now, besides managing hatcheries and stocking programs, they often work as referees, trying to resolve squabbling between catch-and-release anglers and traditionalists and to find suitable and separate waters for each side.

This resulted in the first government stocking of native and non-native species in 1889 and continued with a variety of successful and unsuccessful stocking efforts until 1955 when all stocking programs in the park were discontinued.

Of more serious concern are the genetic risks posed by stocking programs.