Limestone Canyon, a preserved natural area in the Irvine Ranch Open Space, is famous for a striking geological feature called “The Sinks.”
These dramatic eroded cliffs are often referred to as the “mini Grand Canyon” of Orange County, and you can check them out via a moderate 9-mile hike through scenic Californian wilderness.
Public access is restricted to this protected area, so visitors must register in advance to visit Limestone Canyon. Keep reading for a simple overview.
The Sinks and more features of Limestone Canyon
The Sinks
“The Sinks” is the name given to Limestone Canyon’s famous layered sandstone cliffs located in the southern part of the preserve. Millennia of landslides and seismic events exposed the dramatic cliff faces, revealing bright bands of red, orange, and beige rock.
Scientists believe that The Sinks are part of the Sespe formation, estimated to be between 20-40 million years old. Do you see the resemblance to the Grand Canyon?
Year-round springs
Limestone Canyon has several perennial springs that serve as oases for local wildlife and plants. Look for Dripping Springs, a sensitive area with lush wildflowers and ferns, and Box Springs, which has a shady oak canopy.
Visiting Limestone Canyon
Visitors can explore Limestone Canyon via 20 miles of crisscrossing trails, which pass through oak woodlands, grasslands, and seasonal streams. You can hike to a designated viewing deck to check out The Sinks, or otherwise set out on equestrian and mountain biking trails.
Importantly, most of this area burned during the Silverado and Bond fires of 2020, and the landscape is still incredibly sensitive. Visitors can only come on scheduled docent-led “Wilderness Access Days,” which historically happen every few months.
These special days are free to attend, but they tend to fill up quickly on the Irvine Ranch Natural Landmarks website LetsGoOutside.org. The site is currently under maintenance, so keep an eye on it to catch the next Wilderness Access Day.