The activities below are offered by a variety of organizations and their dedicated volunteers. All programs are FREE unless noted below. Programs led by IRC-Certified Volunteers require pre-registration, which closes at 4 p.m. on the day prior to the event. No walk-up registrations will be permitted for these events. For policies of other organizations, please use the sign-up information provided. For mobility device policies click here.
| Note: Minors must be accompanied by a parent or guardian for these events. For programs requiring online registration, each adult and child must be registered. |
Need help? For the fastest answers, look for organization-specific contact information in each event listing (click More Information for full listing). If no contact information is listed, email info@irconservancy.org for assistance.
Updated Difficulty Ratings: The Hiking and Fitness Difficulty Ratings have been updated to reflect our current activities. Please click below to read the ratings.
Click here to learn more about IRC-Certified Volunteers. • Click here to learn more about the Difficulty Ratings.
Search & Filter Activities
Saturday, May 10, 2025
Agua Chinon and the Sinks Exploration Day
Please note: Preregistration is required due to limited parking capacity.
Start your weekend off by exploring the Agua Chinon wash and the Sinks through this self-guided opportunity. Designated trails will be open for self-guided trail use in OC Parks’ Irvine Ranch Open Space. Trail routes vary in distance and level of difficulty with choices ranging from easy one-hour walks to a strenuous 9.5-mile trek. Whether traveling by feet or on two wheels, this exploration day is a treasure waiting to be discovered by hikers and mountain bikers alike. Visitors to the Open Space during this activity are able to hike or bike to the West and East Sinks viewing areas.
Please review our Trail Tips page and FAQ page to prepare for this challenging hiking and biking opportunity.
- Date:
- Sat, 05/10/2025
- Time:
- 8:00 am - 1:00 pm
- Where:
- Limestone Canyon Nature Preserve
- Difficulty Rating:
- Variable
- Distance:
- Variable
- Minimum Age:
- All Ages
- Family Friendly:
- Yes
- Spaces Left:
- Full
Sunday, June 15, 2025
Earthcache Hike to East Sinks
Come and hike with us to the East Sinks in Limestone Canyon, location of the Earthcache site — a special place people can visit to learn about unique aspects of the Earth — listed on www.geocaching.com. The cache is titled “The Sinks- Irvine Ranch Wildlands, GC1ZB6V.” This hike is open to existing geocachers, those curious about geocaching and non-geocachers alike. There will be as much time as needed spent at The Sinks so all geocachers can record their data and make their observations to confidently log their visit to this cache site.
- Date:
- Sun, 06/15/2025
- Time:
- 8:00 am - 12:00 pm
- Where:
- Limestone Canyon Nature Preserve
- Difficulty Rating:
- 4
- Distance:
- 6 miles
- Minimum Age:
- 16
- Spaces Left:
- Registration for this event opens at 8:00am on 05/31/2025
Slow-paced Mountain Bike Ride: Limestone Canyon/East Sinks
Enjoy the relaxation of riding in the wilderness on empty trails. Join us on this docent-led mountain bike ride through Limestone Canyon, part of OCParks’ Irvine Ranch Open Space. We will visit the East Viewing Platform for a panoramic view of the geological feature call The Sinks. The route to The Sinks will include a fun downhill ride on the Dripping Springs single track. The return route will take us on the Limestone Ridge single track with views of Limestone Canyon, Santiago Canyon and the Santa Ana Mountains.
This is a slow-paced ride designed for the beginner that has experience riding fire roads such as Limestone Canyon or Telegraph Canyon but wants to develop their climbing and riding abilities. The ride can also be enjoyed by more advanced riders looking for a relaxed ride in a beautiful setting.
- Date:
- Sun, 06/15/2025
- Time:
- 8:30 am - 11:00 am
- Where:
- Limestone Canyon Nature Preserve
- Difficulty Rating:
- 3
- Distance:
- 11 miles
- Minimum Age:
- 14
- Spaces Left:
- Registration for this event opens at 8:00am on 05/31/2025
Sunday, June 29, 2025
Photo Journey Limestone Canyon: The Sinks, Loma Ridge Backcountry and Sunset
Join us in the back-country wilderness for a journey filled with beautiful sights that are photographic and artistic sketching opportunities. Our journey begins in the afternoon. We will be deep in a secluded canyon, where time is measured in centuries, even millennia, in the sandstone cliffs of this ancient place called Limestone Canyon. You will board a 4-wheel drive vehicle for a 13-mile tour of the canyon and hills surrounding it. We will stop frequently for 15-30 minutes to admire the views, take photos, sketch landscapes, and answer questions.
- Date:
- Sun, 06/29/2025
- Time:
- 4:00 pm - 8:00 pm
- Where:
- Limestone Canyon Nature Preserve
- Difficulty Rating:
- 2
- Distance:
- 16 miles
- Minimum Age:
- 16
- Spaces Left:
- Registration for this event opens at 7:00am on 06/14/2025
