[2] The near seventy square-mile Geronimo Creek watershed lies entirely within the larger Guadalupe River Basin.

The upper part of its tributary, Alligator Creek, is located in Comal county.

Alligator Creek begins on the west side of IH-35 and flows southeast into Guadalupe county.

Today, this watershed offers multiple opportunities for primitive recreation, angling, and hunting.

The creek passes through steep to gently sloped terrain that is surfaced by clay and sandy loams that support scrub brush, honey mesquite, huisache and natural grasses including "Texas spur".