Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Each library location has expert reference librarians available to assist with research and provide answers to reference questions received by phone, fax, or in person. To ask for reference assistance by E-mail, Ask a Librarian at library@usgs.gov.