Recovering the Endangered Sentry Milk-Vetch in Grand Canyon National Park

Sentry milk-vetch (Astragalus cremnophylax var. cremnophylax). NPS photo.
Sentry milk-vetch (Astragalus cremnophylax var. cremnophylax).
NPS photo.

Growing exclusively within 25 feet of the rim in Grand Canyon National Park, the aptly named “sentry” milk-vetch (pea family plant) forms a 1-inch-high mat in shallow pockets of soil on the Kaibab limestone. It is endemic to the park and federally listed as an endangered species. Sentry milk-vetch occurs in only a few populations on the South Rim.

This timeline brings to life the step by step experimentation and learning involved in the slow process of recovering an endangered species. From collaborating with other organizations, to designing experiments, to digging and moving dirt, Grand Canyon NP staff and their partners have patiently devoted themselves to restoring this tiny plant.

Prepared by Sonya Daw, with support from Jean Palumbo and Lori Makarick (Grand Canyon National Park), Southern Colorado Plateau Network Inventory and Monitoring Program, 2015.