One of the seven wonders of the Irvine Ranch Natural Landmarks, “The Sinks” in the Limestone Canyon Nature Preserve, is a hidden gem in Orange County. A geological formation consisting of layered sandstone cliffs, The Sinks are often referred to as Orange County’s Mini Grand Canyon and have become a popular destination for outdoor enthusiasts and photographers.
The red sandstone cliffs that form The Sinks are eroded in the Sespe Formation, a geological formation of southern California which is between 20-40 million years old. Visitors to The Sinks will experience the beautiful reddish-brown sandstone that drops off sharply into the canyon forming a natural bowl.
A spectacular geological formation in Limestone Canyon Nature Preserve, The Sinks is only one of many geological features in the heart of Orange County. The Irvine Ranch Natural Landmarks are an outstanding illustration of the complicated geological history of the southwestern continental margin of North America. The exceptionally wide variety of rock types and diversity of fossils exposed on the land captures changing landscapes and evolutionary events for a span of over 200 million years.
The Sinks is most often accessed during scheduled programs and Wilderness Access Days. To experience the beauty of The Sinks first hand, click the programs below or discover more at letsgooutside.org/activities.
Dec. 16: Afternoon Adult Beginner Mountain Bike Ride: Limestone Canyon to The Sinks on Sunday, December 16 from 2 – 4:30 p.m. will lead bikers through sycamore, oaks and habitat native to California. The route will take participants to The Sinks, stopping to talk about the local habitat along the way.
Dec. 19: Mid-Week Hike: Agua Chinon and the Sinks on Wednesday, December 19 from 8 a.m. – 1 p.m. will give hikers a chance to recharge their batteries with a refreshing mid-week hike through the Agua Chinon Wash in Limestone Canyon Nature Preserve. This hike will visit The Sinks and other possible destinations such as Box Springs, Loma Ridge, Limestone Ridge and Limestone Canyon.
Dec. 21: The Lure and Lull of Limestone Canyon and The Sinks Equestrian Ride on Friday, December 21 from 10 a.m. – 2 p.m. offers a leisurely ride through beautiful Limestone Canyon, home of oak woodlands, grasslands and coastal sage scrub. Riders will view evidence of the old ranch days when cattle once roamed the area, see native wildflowers and some of the designated landmarks of the area.
Most guided programs on the Irvine Ranch Natural Landmarks are free and open to the public with required pre-registration, which closes at 4 p.m. the day prior to each event. For more details on programs on the Irvine Ranch Natural Landmarks and to learn more about this iconic geological formation visit www.LetsGoOutside.org.