An official website of the United States government. Here's how you knowHere'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 () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Latest Earthquake | Chat Share
Cross section through the trunk of a lodgepole pine tree from Cooking Hillside near Mud Volcano, Yellowstone National Park. The earliest date for this tree is 1916 and it died in 1990. Spongy white-gray areas are foam insulation that was injected into the sample to reinforce the structure of the wood.