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.
Ed Pfeifer of the USGS Southwest Geographic Science Team collecting water samples during field work for a study of Dall sheep habitat in Denali National Park, Alaska.
Public Domain.
