PRE-REGISTRATION is REQUIRED for this event. 

All participants are required to present the email confirmation (printed physical copy or digitally on their phone) upon arrival to drive through the entry gate.

You will also need the confirmation email for you and your guests to enter the trail system.

Start your weekend off by exploring numerous opportunities found throughout magnificent Limestone Canyon. 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 strenuous 15-mile cardio treks. Whether traveling by feet or wheels, Wilderness Access Day in Limestone Canyon is a treasure waiting to be discovered by hikers and mountain bikers alike.

Participants will want to plan their day successfully by using Trail Tips to prepare.

Please note that you are asked to adhere to the following measures during the activity in order to participate:

• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire and footwear, first aid, medications, etc.
• Restrooms will be available, but facilities will not be sanitized for each individual.

Additionally, in an effort to respect and protect all employees, volunteers and participants, please do not sign up or attend if you are not feeling well, exhibiting any symptoms of illness, or have been in recent contact with someone who was ill.

Do not stop or park anywhere along Santiago Canyon Road. The entrance gate will not open until 8am.  Anyone stopped or parked along Santiago Canyon Road prior to the opening will be subject to citation. Thank you for your cooperation with regard to the safety of everyone on the road. Please plan your drive accordingly.

This is a natural area characterized by certain inherent dangers including: mountain lions, rattlesnakes, poisonous plants and insects, weather extremes, loose rocks and rugged terrain. The Irvine Ranch Open Space contains rare and sensitive habitat and is under strict protection. Participants are required to stay on designated trails at all times. OC Park Rangers may issue citations for visitors found off-trail. For your safety, please stay on the designated paths during your visit to Limestone Canyon. To learn more about the staging areas and activity locations, please visit our Staging Areas Playlist page.

Other Important Notes:

• Visiting the highly popular “The Sinks” is a 9-mile round trip hike over moderate terrain and can take the majority of the designated event time.
• OC Park Rangers require all trails to be cleared for closure by 2 p.m.
• No new trail users will be permitted onto the trails at least one hour prior to closing.
• Dogs are prohibited on the Irvine Ranch Open Space. By nature, dogs are predators; their presence and their lingering scent disturb the indigenous wildlife and disrupt vital routines long after a dog has left the area.
• Minors, ages 18 and under, should be accompanied by a parent or guardian.
• Adult mountain bikers and equestrians are requested to wear helmets. Minors are required to wear helmets per state law.
• Motorized recreation vehicles of any class or type are not permitted for use in the Irvine Ranch Open Space.
• Inclement weather or fire danger will cause the program to be cancelled.

Multi-use trail etiquette: Please Remember that bikers yield to hikers and that bikers and hikers yield to equestrians. Click here for more trail tips.

To minimize the human impact on wildlife and their habitat, there may be unannounced trail closures or the rotation of areas being open and closed. This is an adaptive management approach to accommodate both the human users and the wildlife needs.

Learn more and register here.