This might be an ok trail run to a point but the closer you are to the canyon the more boulders you have to contend with.
The trail follows a couple of washes to Devil's Den which is a narrow canyon. This canyon is on the north side of Big Bend National Park near the north entrance. This area does not get as much traffic as the Basin, Santa Elena, or Boquillas regions, but it is well worth it to stop for a trip here. You won't have to contend with other runners, and you can enjoy the backcountry feel of the trails in the area.
From the start, you'll head out through a sandy wash, moving through open country. Though the trail isn't maintained, the path is obvious and those with proper navigation skills are encouraged to explore (as long as Leave No Trace principles are followed!). There will be plenty of scrubby desert flora, so longer pants are recommended.
As you continue, the wash will move toward a prominent ridge. As you near the ridge, you'll be able to see the gap through which this wash begins. Continue working your way east as the grade steepens and the open surroundings become a canyon. Running within the canyon becomes difficult near the eastern mouth due to a series of pour-offs and boulders. You'll have to do some scrambling to work your way through! Devil's Den may have some standing water near eastern mouth, so be prepared for potentially wet feet.
To make a full day of it enjoy both Dog Canyon Trail
and Devil's Den as a loop.
Deer, birds, coyote, javelinas, and wildflowers.