Park and grab at a turn out near the intersection of 166 and 505, plenty of parking available. Even though there is little traffic on this road use some discretion in retrieving the container. Bring a pencil or pen to sign the log, use a pencil, pen, or TTOT to help retrieve the container if necessary.
Please, please re-hide the container as found or better, the Border Patrol has a presence here for a reason. As with any other cache in this area make some noise and poke around before reaching for anything, the container is located very near the ground.
If you point your compass at 45 degrees magnetic you can see Mt. Livermore about 9 miles away. At over 8300 feet in elevation it is the highest peak in the Davis Mountains and one of the highest peaks in Texas.