Welcome to the Lake Eaton Sinkhole!
This quest will take you roughly three miles, along the sinkhole trail. There is very little bushwhacking involved.
You will start at the posted coordinates, where you will see three verticle yellow reflectors. This starts your reflector trail. Head south, and follow the yellow reflectors, along the sinkhole trail, which will eventually lead you to a man made structure. Time has not been kind to this structure, so as you descend, following the reflectors, exercise caution. You will encounter rotten boards, and occasional holes. Either of these could seriously ruin your day. At the end of the reflector trail, look for two horizontal yellow reflectors. At those two reflectors, you will find a soda bottle preform, with the coordinates to an ammo can. Follow the red reflectors back to your vehicle, and you will pass the ammo can, on your way.
Some night cache etiquite:
Headlamps work best for these, though any decent flashlight should do the trick. The reflectors are mostly about 100' apart, so you won't be able to see one, from whatever reflector you are at. If you have doubts about which trail to follow, stand by your current reflector, and send someone expendable, forward, to hunt for the next one. You should bring lots of bug spray, some snackage, and water to drink, along your way.
If you have not already logged it, check out this most excellent virtual cache, Sinking Low. https://coord.info/GCB73C