“A loose, rocky, rutted ascent to an overlook of the main ranch and the Hill Country to the east.
— Lost Justpastnowhere
This is the main trail from the visitor center used to access the West Peak Overlook. From West Peak, you'll have a 360-degree view of the park. (The surprisingly named East Peak, which is not accessible by any trail, is directly east of West Peak and forms part of the Twin Peaks formation).
The ascent to (and descent from) the overlook is very difficult, but it's worth carrying the bike to the top if you can't ride the whole way for the view. You'll have to pick a line through the loose limestone bedrock being careful to dodge the cacti guarding the side, but with a few tries you can probably master the climb in the saddle.
Because the trail is the most direct way from the visitor center to the best vista in the park, it sees more hikers than the farther reaches of the park so expect to see hikers and equestrians on this trail. On the other hand, I've never seen more than a few people in the whole park, so "busy" is relative.