Fossil Falls is a former waterfall that was formed when a lava flow dammed a river. The water wore interesting patterns in the volcanic basalt. The trail to the falls is 1/3 mile from the day use parking, or 1/2 mile from the campground. At the falls you can climb the rock formations.
The campground is 11 sites, about half not recommended for RVs. Vault toilet, picnic tables, and fire pits are what you get for the $6/night fee. (Pay the iron ranger.) Verizon signal is good, no TV. Trucks from the nearby gravel mine start making noise early. (The wide road goes to the mine.)