An official website of the United States Government 
Here's how you know

Official websites use .gov

A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS

A lock ( lock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Photos

Snapshots of what’s happening in the Defense Department.

Grass older than 10,000 years has maintained enough chlorophyll to keep its green coloring within permafrost in Alaska.

Lighting the Way

Gary Larson, the facility operations manager with the Cold Regions Research and Engineering Laboratory, points out grass older than 10,000 years that has maintained enough chlorophyll to keep its green coloring within the permafrost during a tour of the U.S. Army Corps of Engineers Permafrost Tunnel on Sept. 12, 2019. The only one of its kind, the Army and CRREL maintain the permafrost tunnel to allow research on permafrost and how it affects climate change.

Photo Gallery