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.
This deep hole is the western pit of the Double Sinks along the El Calderon Area trail. The trail straddles a saddle between two great lava tube pits of the Double Sinks (see NPS, 2009a,b).
Public Domain.
