In late February 2003, Hal Cohen began watching the Turkey Vulture migration in the Borrego Valley. To his surprise, kettles of Swainson’s Hawks began to appear daily. The final count for Swainson’s Hawks in that first year was 2,031.

In 2004, the first training session for volunteers was organized. Today, with the sponsorship of the Anza-Borrego Desert Natural History Association, there is an established group of volunteers to monitor the migration from mid-February to early or mid-April.