Nicknamed Prairie Dog Town, Los Posos Gulch runs northeastward from East Yucca Farm Road towards cottonwood-lined Cienaga Creek. Blacktail Prairie Dogs disappeared from the Arizona ecosystem in the 1930s. The Las Cienegas National Conservation Area is reintroducing them in a project along this trail. A pullout serves as an observation area for the burgeoning prairie dog town.
The trail starts wide and well maintained with several RV-sized campsites near the trailhead. The track tightens and becomes rougher after the prairie dog town, with grass growing in the middle. The trail parallels the lush Cienaga Creek drainage before unceremoniously ending at a fence with little room to turn around. One small spur goes off southward to a small pond.