Come out and enjoy this family-fun activity on the Mesa. We will start with an activity to make your own fossil, then we will take a 2–3-mile hike looking for fossils deposited here in Orange County millions of years ago when Orange County was a sea. A slight elevation gain (200 feet) to start the hike will give incredible views of the surrounding peaks and the red rock cliffs of Black Star Canyon. Wear comfortable shoes, bring water and enjoy an early morning hike in this intriguing region.

Please note that you will be asked to adhere to the following measures in order to participate:

• Be registered in advance, no walk-up registration is permitted.
• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire, and closed-toe footwear, first aid, health needs etc.
• Restrooms will be available, but facilities will not be sanitized for each individual.
• All participants are required to sign a liability waiver upon arrival at the staging area and before beginning the activity. The waiver can be previewed here: IRC Liability Waiver
• You may be prevented from participating if you do not adhere to the above protocols.

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.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-2 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering. To learn more about the staging areas and activity locations, please visit our Staging Areas Playlist page.

Learn more and register here. 

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.

All participants are required to check-in and complete their registration at the Portola Staging Area prior to accessing the trail system. Gates will open no earlier than 8 a.m. The West Sinks route is 6 miles round trip with a challenging hill climb while a visit to the east viewing deck is a strenuous 8 miles round trip and may take the majority of the designated activity time. Registration for this event is limited to 50 participants. Be sure to cancel your registration if you cannot attend, so that other participants can register. No walk-up registrations will be allowed.

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 Parks Rangers may issue citations for visitors found off-trail. For your safety, please stay on the designated paths during your visit to Agua Chinon. To learn more about the staging areas and activity locations, please visit our Staging Areas Playlist page.

Other Important Notes:

• OC Parks Rangers require all trails to be cleared for closure by 1:00pm.
• No new trail users will be permitted onto the trails beginning 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 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 when sharing the trails. 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. 

Experienced mountain bikers can explore one of the most rugged and remote areas of OC Parks’ Irvine Ranch Open Space from the trails of Fremont Canyon Nature Preserve on this moderate-paced ride through Fremont, Blind, and Weir Canyons. Fremont Canyon remains one of the most wild places in Orange County, with a diversity of rare plants and animals. This ride includes natural trail hazards such as sand, tree roots, ruts, and exposed rocks.  PLEASE NOTE: there are multiple very steep climbs, with an approximate elevation gain of 2,000 feet over 15 miles.  This hard ride is for adult-only riders in excellent physical condition who will be rewarded with the beautiful vistas. Motorized recreation vehicles of any class or type are not permitted for recreational use.

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

• Be registered in advance, no walk-up registration is permitted.
• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire, and closed-toe footwear, first aid, health needs etc.
• Restrooms will be available, but facilities will not be sanitized for each individual.
• You may be prevented from participating if you do not adhere to the above protocols.

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.

Please review the Difficulty Ratings to help you evaluate your readiness to participate in this level-5 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering.

Learn more and register here. 

Come join us for an interactive evening under the stars.  Immerse yourself in a scaled-down version of our solar system.  Test your imagination in naming the constellations.  Reenact the struggle between Orion and the Scorpion.  The hike will average 2-3 miles round trip at an easy pace with a high level of interpretation. This program is for participants who would like a slower-paced hike. Wear comfortable clothes and sturdy shoes and bring water for the hike. This activity is designed with kids ages 5 – 12 in mind but, everyone is welcome.

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

• Be registered in advance, no walk-up registration is permitted.
• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire, and closed-toe footwear, first aid, health needs etc.
• Restrooms will be available, but facilities will not be sanitized for each individual.
• All participants are required to sign a liability waiver upon arrival at the staging area and before beginning the activity. The waiver can be previewed here: IRC Liability Waiver
• You may be prevented from participating if you do not adhere to the above protocols.

Children under the age of 5 are permitted to attend the hike if they are secured in a carrier for the duration of the hike. Strollers or all terrain wagons are not permitted.

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.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-2 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering.

Learn more and register here.

Take a leisurely ride on beautiful Hall Canyon and Helo trail in the Black Star Wilderness Area, home of oak woodlands, grasslands, and coastal sage scrub. View evidence of the old ranch days when cattle once roamed the area and see wildflowers that are native to our area. You will see amazing views of the local canyons and red rock. Evidence of a more recent use of the land is an area used for helicopter landings and a large metal ball and chain the military and OC Fire departments used for training.

Equestrians who have trail riding experience, and their own fit and able horse are welcome. You will need to transport your horse to the staging area. Owners of unshod horses, please note that footing will include areas of gravel, rocky creek areas.

Please note that you will be asked to adhere to the following measures in order to participate:

• Be registered in advance, no walk-up registration is permitted.
• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire, and closed-toe footwear, first aid, health needs etc.
• You are welcome to arrive 30 minutes prior to listed departure time to ready your horse.
• We will be contacting you for trailer details so we can give you direction on where to park it.
• Restrooms will be available, but facilities will not be sanitized for each individual.
• All participants are required to sign a liability waiver upon arrival at the staging area and before beginning the activity. The waiver can be previewed here: IRC Liability Waiver
• You may be prevented from participating if you do not adhere to the above protocols.

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.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-3 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering.

Learn more and register here. 

Take a leisurely equestrian ride through beautiful Limestone Canyon, part of OC Parks’ Irvine Ranch Open Space, and home of oak woodlands, grasslands, and coastal sage scrub. On a clear day this ride has beautiful views of Orange County and Catalina Island. This ride includes an approximate 900 foot climb in elevation.  We will either return via dripping springs trail or hicks haul road (asphalt) depending on trail conditions.

Equestrians must have their own horse, trail riding experience, and the ability to transport their horse to the staging area. Horses must be fit, able to comfortably ride the distance as described, and be well-behaved in a group. This walking equestrian ride travels on single-track and wide fire roads. It may include a moderate, steady climb. Owners of unshod horses, please note that the footing may include areas of gravel and pavement.

We welcome riders who have their own horse and trail riding experience. Both rider and horse must be fit for 3-plus hours over moderate terrain, including hills. This ride travels on wide trails and single tracks with several moderate to steeper climbs as well as steep descents. . You will need to transport your horse to the staging area. Owners of unshod horses, please note that footing will include areas of gravel and distances over asphalt pavement. Please bring water on the ride.

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

• Be registered in advance, no walk-up registration is permitted.
• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire, and closed-toe footwear, first aid, health needs etc.
• Restrooms will be available, but facilities will not be sanitized for each individual.
• All participants are required to sign a liability waiver upon arrival at the staging area and before beginning the activity. The waiver can be previewed here: IRC Liability Waiver
• You may be prevented from participating if you do not adhere to the above protocols.

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.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-3 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering. To learn more about the staging areas and activity locations, please visit our Staging Areas Playlist page.

Learn more and register here. 

Spend your morning helping to remove weeds and rebuild berms within the butterfly habitat islands in Limestone. With your help we will be able to maintain “islands” of host and nectar plants for butterflies in decline in Limestone Canyon. You will be transported from via a safari style truck from butterfly island to butterfly island through a beautiful oak woodland.

Please note that you will be asked to adhere to the following measures in order to participate:

• Be registered in advance, no walk-up registration is permitted.
• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire, and closed-toe footwear, first aid, health needs etc.
• Restrooms will be available, but facilities will not be sanitized for each individual.
• All participants are required to sign a liability waiver upon arrival at the staging area and before beginning the activity. The waiver can be previewed here: IRC Liability Waiver
• You may be prevented from participating if you do not adhere to the above protocols.

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.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-2 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering.

Learn more and register here. 

Join us every Wednesday night in OC Parks’ Irvine Ranch Open Space for a fitness-focused hike on the paved Hicks Haul Road. During the spring, summer and fall, hikers will enjoy wonderful sunset views and a panoramic overview of Orange County. This hike travels about 3.5 miles, up to the top of Loma Ridge and back down. The hike is conducted at an average of 3-3.5 miles per hour, but you may travel a bit faster or slower, at a walk, run, or jog depending on your comfort level. Most participants finish the route in about 1 hour. Because of the paved surface of the road, you may wear regular running or walking shoes. Trail shoes are fine, but not required. Please bring adequate water.

Please note that you will be asked to adhere to the following measures in order to participate:

• Be registered in advance, no walk-up registration is permitted.
• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire, and closed-toe footwear, first aid, health needs etc.
• Restrooms will be available, but facilities will not be sanitized for each individual.
• All participants are required to sign a liability waiver upon arrival at the staging area and before beginning the activity. The waiver can be previewed here: IRC Liability Waiver
• You may be prevented from participating if you do not adhere to the above protocols.

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.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-3 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering.

Learn more and register here.

Join us for a tour to the dramatic sandstone outcrops known as “Mini Moab”. We’ll hike out-and-back along the high ridges overlooking Fremont Canyon. Along the way we’ll pass an abandoned coal mine, the Fremont Canyon Weather Station, and Lizard Rock. Bring a snack to enjoy while taking in the views at our destination. Distance is 14 miles with 2900 feet of elevation gain at an average of 3 mph – designed for advanced hikers. Periodic brief breaks are planned. Participants must be physically fit and have distance hiking experience.

Please arrive 15 minutes early and bring a minimum of 100 oz. water and trail snacks. Come prepared with a pack, sturdy closed-toe hiking shoes or boots, sunscreen, first aid, and all other supplies to keep you safe and healthy on the trail for the full-day hike in this remote wilderness area. Each participant must carry his or her own sturdy pack and must be comfortable maintaining an average moving pace of 3 miles per hour for the duration of this difficult hike. Under-prepared participants may be denied access to this activity.

Please note that you will be asked to adhere to the following measures in order to participate:

• Be registered in advance, no walk-up registration is permitted.
• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire, and closed-toe footwear, first aid, health needs etc.
• Restrooms will be available, but facilities will not be sanitized for each individual.
• All participants are required to sign a liability waiver upon arrival at the staging area and before beginning the activity. The waiver can be previewed here: IRC Liability Waiver
• You may be prevented from participating if you do not adhere to the above protocols.

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.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-5 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering.

To learn more about the staging areas and activity locations, please visit our Staging Areas Playlist page.

Learn more and register here. 

Join us for a fitness-focused hike on the paved Hicks Haul Road in the Irvine Open Space Preserve. During the spring, summer and fall, hikers will enjoy wonderful sunset views and a panoramic overview of Orange County. This hike travels about 3.5 miles, up to the top of Loma Ridge and back down. The hike is conducted at about 3-3.5 miles per hour, but you may travel a bit faster or slower, at a walk, run, or jog depending on your comfort level. Most participants finish the route in about 1 hour. Because of the paved surface of the road, you may wear regular running or walking shoes. Trail shoes are fine, but not required. Please bring adequate water and a red-tinted flashlight as the return portion of the hike may be after sunset.

Please note that you will be asked to adhere to the following measures in order to participate:

• Be registered in advance, no walk-up registration is permitted.
• Arrive with all necessary equipment to keep you safe on the trail, including water, proper attire, and closed-toe footwear, first aid, health needs etc.
• Restrooms will be available, but facilities will not be sanitized for each individual.
• All participants are required to sign a liability waiver upon arrival at the staging area and before beginning the activity. The waiver can be previewed here: IRC Liability Waiver
• You may be prevented from participating if you do not adhere to the above protocols.

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.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-3 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering. To learn more about the staging areas and activity locations, please visit our Staging Areas Playlist page.

Learn more and register here.