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.
The Pfafstetter code is based on the methodology. Within a watershed boundary, the mainstem streamline is numbered one, and the four largest tributaries off the mainstem are assigned even numbered basins (2, 4, 6, & 8)
Public Domain.
