When the Lacey Act, named for Representative John Lacey of Iowa, was passed in 1900 it became the nation's first far-reaching federal wildlife protection law. The act was prompted by growing concern about interstate profiteering in illegally taken game. It was amended in the 1930s and 40s, and again in 1981.

Under the Lacey Act today, it is illegal to import, export, sell, acquire, or purchase fish, wildlife or plants taken, possessed, transported, or sold:
in violation of U.S. or Indian law, or
in interstate or foreign commerce involving any fish, wildlife, or plants taken possessed or sold in violation of State or foreign law.
The law covers all fish and wildlife and their parts or products, and plants protected by the Convention on International Trade in Endangered Species or State law. Commercial guiding and outfitting are considered "sales" under the Lacey Act.
Injurious Wildlife Provisions of the Lacey Act
The Lacey Act was amended in 1949 to prohibit import of wild vertebrates and other animals listed in the Act or declared by the Secretary of the Interior to be injurious, except under certain regulated conditions, such as for research or museum display.
Declaring a species injurious involves a five-step process: Petition, Notice for Information, Record of Compliance, Proposed Rule, and Final Rule. The Service may initiate a proposed rule without a petition or notice for information if the scientific data support a listing. The Lacey Act does not set a time frame for making "injurious" determinations. It typically takes 12 to 18 months complete the evaluation and publish a Final Rule. Currently, 16 species, or groups of species, are listed as "injurious" under the provisions of the Lacey Act.
Enforcement Provisions of the Lacey Act
The Act sets fines for violations involving imports or exports, or commercial violations in which the value of the wildlife exceeds $350. Fines for misdemeanor violations are currently set at a maximum of $100,000 for individuals and $200,000 for organizations. Maximum fines for felonies are presently $250,000 for individuals and $500,000 for organizations.
Officers enforcing the Lacey Act may carry firearms; make arrests; search and seize; issue subpoenas and warrants; and inspect vessels, vehicles, aircraft, packages, crates, and containers on arrival or departure from the United States. The law authorizes rewards for information leading to arrests, criminal convictions, civil penalties, or forfeiture of property, and for payment of costs of temporary care for fish, wildlife, or plants needed for court proceedings.