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.
Flood basalt lava flow in stacked layers viewed eastward across the Columbia River from Rowena Crest Viewpoint, Oregon. Basalt in the lava flows has formed columnar jointing.
