Brocken Track, the second region in RAGE 2, has 2 Authority Sentries. They are scattered around the entire region. Authority Sentries are large objects visible from a distance. Destroy them to get money, points, and unlock new activities. This page in our guide to RAGE 2 contains locations of all Authority Sentries found in Brocken Track.
Authority Sentry near Razorneck Ravine
This Sentry is in the eastern part of Brocken Track, near Razorneck Ravine.
Destroy it by shooting its center with the guns mounted on your vehicle. However, a better idea is to leave the vehicle and hide behind the metal parts located near the Sentry. Its attacks are easier to avoid here.
Authority Sentry near Yeoman Growery
This Authority Sentry is at the top of Brocken Track. To reach it, you have to move north. An exploration spot and Yeoman Growery (Bandit Dens) are located near that place.