Agua Chinon to the Sinks and Box Springs
- Location: Northeast Irvine in the Santa Ana foothills. The Portola Staging Area is located at the eastern end of the Irvine portion of the Portola Parkway. From I-405 or I-5, take the Sand Canyon exit and head north east (2.5 miles from I-5, 4.5 miles from I-405) to Portola Parkway. Turn right and follow Portola to its ending just beyond the 241 Toll Road. Turn left and drive a short distance to the Portola Staging Area, where signs will direct you to parking. If you are taking the 241 Toll Road, use the Portola Parkway exit in Irvine (not the Portola Parkway exit farther south in Foothill Ranch). Head east into the park and follow the signs to the staging area.
- Agency: Irvine Ranch Conservancy/Limestone Canyon Wilderness Park
- Distance: 6.6 miles
- Elevation gain: 950 feet
- Suggested time: 3 hours
- Difficulty rating: PG-13 (distance, elevation gain)
- Best season: Year round but hot during the summer; accessible only on scheduled days through the Irvine Ranch Conservancy (see link above for dates)
- USGS topo map: El Toro
- Recommended gear: sunblock; sun hat
- More information: Trip descriptions here and here; description of upcoming hike on 9/4/14 here; Everytrail report here
- Rating: 7
You already know how to reach the Sinks, the “Grand Canyon of Orange County” from the north, so in this post, we’ll look at the route from the south. Unlike the north approach, which can be done on the Irvine Ranch Conservancy’s Wilderness Access Days, this route can only be done as a docent-led group hike. The exact route described here is usually offered once per month; longer or shorter variations are also offered. Because this area sees very little human traffic, the chance of a wildlife sighting is greater.
From the parking area, the route heads briefly southeast, passing through a gate and paralleling the 241 Toll Road. At about 0.4 miles, you bear left and begin heading up into Agua Chinon (“Wavy Water”) Canyon. The trail ascends at a gentle pace for the next mile and a half before becoming steep. As you grind up the hill, your efforts are rewarded with an excellent view of the Sinks; you may also see Modjeska and Santiago Peaks poking above the ridges to the east.
The trail makes an S-curve and finally levels out at about 2.7 miles from the start, where you reach a junction by a watering trough. Head straight for a short distance where you reach an observation platform, from which you can get an aerial perspective on the Sinks. The 150-foot high formations were created by the erosion of soft sedimentary rock, creating layers of pink, brown, orange and purple.
After enjoying the panorama, return to the junction and follow the East Loma Trail northwest through an attractive grove of live oaks. At a T-junction in a meadow, turn left and descend to another junction where you turn left a second time and re enter the woods. Here is Box Springs, a seasonal spring pleasantly located beneath several towering oak trees. Especially on hot days, this is a peaceful spot to sit and relax before heading back. There’s a little elevation that has to be made up on the return trip, but most of it is downhill and views of the Orange County coastal plains from the hill provide a finishing touch to this hike.
Text and photography copyright 2014 by David W. Lockeretz, all rights reserved. Information and opinions provided are kept current to the best of the author’s ability. All readers hike at their own risk, and should be aware of the possible dangers of hiking, walking and other outdoor activities. By reading this, you agree not to hold the author or publisher of the content on this web site responsible for any injuries or inconveniences that may result from hiking on this trail. Check the informational links provided for up to date trail condition information.