Sportsman Pass is required for entry. Annual pass is $30 and 3-day pass is $5.
The outer Loop is one of the classic Camp Robinson Trails; you'll find it on the oldest versions of the maps of the trails. It's a point to point trail and technically not a loop. It starts at Center Road across from Yucca and weaves through the woods as wraps around Porta Potty and 'intersects' with Airport, Buddha, and Porta Potty. The first part of the trail (starting at Center Road) is relatively smooth. The character of the trail changes quickly past the junction with Porta Potty at which point it becomes rocky and tight.