COLUMBUS, New Mexico (AP) — Orange no-entry signs posted by the U.S. military in English and Spanish dot the New Mexico desert, where a border wall cuts past onion fields and parched ranches with tufts of tall grass growing amidst wiry brush and yucca trees.

The Army has posted thousands of the warnings in New Mexico and western Texas, declaring a “restricted area by authority of the commander.” It’s part of a major shift that has thrust the military into border enforcement with Mexico like never before.