Distance: 10 miles round trip on trail
Summit Elevation: 1775'
Elevation Gain: 1270'
Elevation Gain (in Empire State Buildings): 1.01
Round trip time: 3 hours 15 minutes
Recommended water: 36 oz.
Parking/Fees: Free at Augustine Staging Area (registration required)
Irvine Ranch Conservancy manages 40,000 acres of open space in eastern Irvine. The area is closed to the public except for docent led events and occasional open access days. The gem of Irvine Ranch is The Sinks in Limestone Canyon. The Sinks is sometimes hyped as the "Little Grand Canyon" of the OC. To register for events, go to letsgooutside.org. I have generally avoided the Irvine Ranch area because, sometimes, they are a bit heavy handed in their management. I decided that it was worth the effort to see The Sinks at least once so I signed my wife and I up for a cardio hike that went past it.
Out of 25 people that signed up, only 4 showed. There were 3 guides so we ended up with essentially a private guided hike. After the first mile on Limestone Canyon trail, the group seemed to be relatively strong, so the guides suggested we take the Sandtrap trail for a loop over Loma Ridge. It was more gain, but gave us great views back into the Open Space, the Santa Anas, and the ocean (through some haze). We kept a brisk pace up to the ridge, taking only one break for water and photos. The trail passes over Peak 1775, the high point on the ridge. On the way down, we stopped to look at a raptor nest before reaching the west viewing platform for The Sinks. Here we took about a 5 minute break for photo ops. I admit my expectations were low, but the The Sinks were an impressive product of erosion for Orange County. The way back was mostly flat, gradually losing about 350' in elevation. The highlight on the way back was a large red tailed hawk at the top of a tree. Counting all breaks, we still averaged over 3 mph over 10 miles. Not a bad workout, though my heart rate was only high during the uphill sections.