Trampas Medio campground is about 1/4 mile from the Trampas Lakes trailhead and perhaps 1/2 mile from the San Leonardo Lakes trailhead where FR 207 and FR 639 meet. If you're coming from 207 (a much better road), you must cross a stream. When I was there in July it was running about 18"-24". Coming from 639 requires a high-clearance vehicle and good shocks, and if it's been wet you may encounter serious mud.
The campground has 3-4 campsites. Though there's not a ton of separation between the sites, you're not on top of each other. This seems to be a favorite for folks bringing truck-bed or tow-behind campers, ATVs and motorbikes.
The sites are right along the Rio de las Trampas, which provide good water (as always, treat before use) and great white noise.