This loop would make a great moderate-difficult trail run, given the variety of terrain and distance.
There is limited parking on Rimcrest Drive, so come early to get a spot.
The trailhead at Rimcrest Drive will place you on South Ridge Trail
where you are immediately presented a wide doubletrack/dirt road. You'll soon be running through rolling hills surrounded by a variation of grassland and sage brush, wide open vistas of the park, and neighboring Yorba Linda and Orange County. Although quite dry in the wintertime, springtime is the best time to see the park's blossoming, colorful sage from an upland vantage point.
As you continue your way due east on South Ridge Trail
, the rolling hills continue along until it intersects with Bovinian Delight Trail
. At this point, you'll start making your way down into the riparian part of the park, and in my opinion, the highlight and scenic section of this loop!
As you make your way on Bovinian Delight Trail
, you'll be running mostly on singletrack, followed by a short stretch of doubletrack/dirt road, and then back on to singletrack until it meets at Four Corners. This is where most of the major trails in the park meet. At Four Corners, you'll find a couple of resting tables with shade and a fairly old porta-potty (as of this posting). Four Corners tends to be a popular resting place to meet up with other visitors and/or bikers, given the number of trails that meet at this intersection.
From Four Corners, you return towards the trailhead via Telegraph Canyon Trail
, which is the highlight of this route! It consists of a doubletrack/dirt road cutting through the center of the park. The trail is the more pleasant, scenic, and shady part of the loop, consisting of stretches of willow and sycamore trees standing above wild rose, stinging nettle, and mule fat.
At the junction with Easy Street Trail
, take a left to head south on this short singletrack, which will return you to the trailhead at Rimcrest Drive.