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 red line represents the strontium isotope ratio for a Ponderosa tree stump found in the West Plaza of Pueblo Bonito (JPB-99). There is considerable overlap in strontium isotope ratios in the Chaco and Chuska regions.
