Delilah contacts you, and after some coded talk, she manages to convey to you that you should go to Cottonwood Creek.
Head to the medicine wheel and get on the path south of it, or go due south to Ruby River and then turn west when you can (you'll see a big tree you can use as a landmark). Either way will lead you to Cottonwood Creek and your destination, Cache Box 308.
Open it using the all-new super-secure code Delilah gives you, and you'll have a new walkie-talkie that's hopefully not being monitored.
Now it's time to explore the mystery of Wapati Meadow. Use whatever combination of paths you like to make your way back to the fence. The gate is no match for your trusty axe — pry it open and proceed. The clipboard hanging near the gate is not terribly informative, plus you get a bee sting trying to read it!
Keep moving into the compound. Any time you see a tower or piece of equipment, you can report on it to Delilah. Both of you are getting more nervous and freaked out by the minute.
At the end of the compound is a tent with lots of stuff to investigate, but the major item is in a box near the front of the tent. Open the box to collect the wave receiver, which replaces your simple compass for the remainder of the game.
The receiver’s beeping leads you to the table at the back of the tent, where there are some really freaky-looking reports to collect. Move them aside to discover the tracking device that caused the wave receiver to go crazy, and turn it off.
Speaking of going crazy, Delilah is encouraging you to burn the place to the ground. No matter how you respond, you'll leave without lighting a match. Head back to the entrance, jump over the gap in the stone bridge, triggering a scramble as it collapses, then talk to Delilah.
But wait! The day's not over yet!
Later that night, you're talking to Delilah in your tower when the wave receiver starts beeping again. Grab it and follow the directions it gives you.
Head south towards the Ruby River, then turn west and head toward the medicine wheel, clearing gaps in the brush as you go. Before you get to the medicine wheel, you'll see it — a backpack with camping equipment and the key to the locked cave!
Use your trusty Pulaski to violently "disable" the alarm behind the pack and call Delilah. What she says will make you race back to your tower, where you'll discover a Walkman taped to the door. The day ends after you talk to Delilah about the tape.