Those black pants turned out to be too hot.
Here's the main mountain bike path. Everyone gets lost and just rides around until they exit. On my second ride, I got lost pretty quickly and ended up on the Juniper Cliffside trail. Fortunately that was loads of fun and plenty challenging.
The lighthouse formation seems to be the signature landmark of the park. It's not very large, but it's very distinctive, so I can see how that would be a great landmark for getting your bearings. The lighthouse trail is the most boring for mountain biking, and I would just save that for hiking. It's meant to be a horseback riding trail (and hiking).
Now that I have my bearings, next time I will actually ride the route recommended on the website: The Givens, Spicer & Lowry running trail and the Capital peak trails.