Select a language:

Beginner Mountain Bike Ride to The Sinks

If you are a beginner rider and perhaps have just completed one of the IRC mountain biking clinics or just want an enjoyable and relaxed ride in the Orange County wilderness, then join us on this docent led, group mountain bike ride in Limestone Canyon Nature Preserve.

This ride starts at the Augustine Staging Area in Limestone Canyon Nature Preserve and rides out Limestone Canyon Road to the geological feature call The Sinks. The ride is about 8 miles long and climbs slightly on the outbound portion, with no significant climbs, but does roll up and down throughout the route and has a total elevation gain of about 450 feet. Note this is the same route as the Evening Beginner Family Ride, just riding the route in the morning.

While not required, participants may consider first riding similar trails like Telegraph Canyon Road in Chino Hills State Park or Trabuco Canyon Road in O’Neill Regional Park.

Riders should bring sufficient water and food for a 2+ hour ride and carrying tools for any trail side repairs is always recommended.

Please review the 1-through-5 Difficulty Ratings to help you evaluate your readiness to participate in this level-2 activity on the land. Note that Electric Mountain Bikes of any class or type are not permitted.

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. Motorized recreation vehicles of any class or type are not permitted for use in the Nature Preserve.

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.


Learn more and register here.

Mountain Bikers riding through Limestone Canyon

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.

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. Motorized recreation vehicles of any class or type are not permitted for use in the Nature Preserve.

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.

Learn more and register here.

Mountain Bikers riding through Limestone Canyon

Mountain Bike Ride at Fremont to Lizard Rock

Join us in OC Parks’ Irvine Ranch Open Space for a challenging, docent-led mountain bike ride through Fremont Canyon to the unique geological formation known as Lizard Rock. This 16-mile out-and back ride, with approximately 2,500 feet of elevation gain is designed for experienced off-road riders in excellent cardio shape and will take up to 3 hours to complete.

The ride begins at the Weir (Outdoor Education Center) Staging Area inside Irvine Regional Park. We’ll climb out of the park on Coal Mine Road, passing the Fremont Canyon Weather Station and a grove of rare Tecate Cypress. Upon reaching Lizard Rock, you’ll be rewarded with spectacular views of upper Fremont Canyon, Sierra Peak, Cathedral Rock, and a sandstone formation locally known as Mini-Moab. We will return to the staging area via the same route.

While the ride is entirely on fire roads, be prepared for steep sections (both uphill and downhill) and potentially loose rocks and soil. We’ll regroup and rest as needed, with multiple opportunities for snack and water breaks.

This ride is entirely on fire roads, but includes sections that are steep (both up and down) and potentially will have loose rocks/soil. The ride will regroup and rest as needed and multiple opportunities will be provided for a snack break.

Please note, the ride is a challenging 16 miles long, with approximately 2500 feet of elevation gain and will take up to 3 hours to complete. It is important that participants bring sufficient food and water for a ride of this difficulty and duration. This program originates at the Weir (Outdoor Education Center) Staging Area inside Irvine Regional Park and ventures into the Fremont Canyon Wilderness Park, the Weir Canyon Wilderness Park, the Coal Canyon Ecological Reserve and the Cleveland National Forest.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-5 activity on the land. Electric Mountain Bikes of any class or type are not permitted.

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.


Learn more and register here.

Mountain Bike Ride, Limestone Canyon

Mountain Bike Ride at Fremont and Weir Canyons to Sierra Peak

Join us in OC Parks’ Irvine Ranch Open Space for a challenging docent-led mountain bike ride for very experienced off-road riders in excellent cardio shape through Fremont and Weir Canyons to Sierra Peak.

We will climb out of Irvine Regional Park on Coal Mine Road to the Fremont Canyon Weather Station and then continue on past the Tecate Cypress grove, Lizard Rock and Mini-Moab on the way to Sierra Peak . We will return to the staging area via much of the same route but will finish by riding through Upper Blind Canyon to Weir Canyon.

This ride is entirely on fire roads, but includes sections that are steep (both up and down) and potentially will have loose rocks/soil. The ride will regroup and rest as needed and multiple opportunities will be provided for a snack break.

Please note, the ride is a challenging 25 miles long, with approximately 4100 feet of elevation gain and will take up to 5 hours to complete. It is important that participants bring sufficient food and water for a ride of this difficulty and duration. This program originates at the Weir (Outdoor Education Center) Staging Area inside Irvine Regional Park and ventures into the Fremont Canyon Wilderness Park, the Weir Canyon Wilderness Park, the Coal Canyon Ecological Reserve and the Cleveland National Forest.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-5 activity on the land. Electric Mountain Bikes of any class or type are not permitted.

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.


Learn more and register here.

Mountain Bikers riding through Limestone Canyon

Open Space Invaders: Invasive Plant Removal at Agua Chinon

Non-native and invasive plant species are invading our native habitat and open spaces. They aggressively compete with our native plants for resources and spreads rapidly once established. Monitoring, management, and removal of these plant species is an important aspect of land management and habitat restoration.

Help us to manage populations of invasive plants and remove them from the habitat. No previous experience is necessary, just a desire to work outside and get dirty! Snake chaps, gloves, and tools will be provided but please feel free to bring your own if you have them. Please wear long pants, long sleeved shirts, close toed shoes, and protective sun protection. Note: This is a wilderness area, there are natural hazards. Snakes, including rattlesnakes, are occasionally seen here.

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.


Learn more and register here.

Invasive Plant Removal at Agua Chinon

Enjoy Nature's Vistas on Long Tour to Mini Moab

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.

A view from Mini Moab overlooking Fremont Canyon

Early Morning Hike: Gypsum Canyon Wilderness

Come explore beautiful Gypsum Canyon Wilderness, the northernmost portion of OC Parks’ Irvine Ranch Open Space. This scenic hike involves steepish climbs and descents on several single-track trails and is done at an average moving pace of 3 miles per hour. The rewards are many: panoramic views of Fremont and Weir Canyon Nature Preserves and beyond, possible wildlife sightings, interesting rock formations, and beautiful wildflowers in season.

Please come prepared with a sturdy day pack, water, snacks, closed-toe hiking shoes or boots, sunscreen, first aid, and all other supplies to keep you safe and healthy on the trail. All participants must carry their own day pack and water and be comfortable hiking an average moving pace of 3 miles per hour. Underprepared participants may be denied access to this activity.

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-4 activity on the land. Please review our Trail Tips and FAQ pages to ensure you arrive prepared for this hike.

Learn more and register here.

Gypsum Canyon Wilderness

Group Stewardship Limestone Canyon Butterfly Habitat Islands

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.

Monarch butterfly sits on a white poppy

After Work Fitness Hike on Paved Hicks Haul Road

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.

Hikers on Hicks Haul Road

Limestone and Red Rock Night Ride

Join us for an evening/night mountain bike ride through Limestone Canyon Nature Preserve and Red Rock Wilderness, part of OCParks’ Irvine Ranch Open Space. We will ride approximately 12 miles, with 1500′ of climbing along a variety singletrack trails and ranch roads. The route will vary based on trail conditions/availability.

This ride is not recommended as a first time night ride. Bring adequate lights, a jacket, plenty of water, spare tubes, tools and all other equipment to be self-sufficient on the trails. Hopefully we will see some of our local nocturnal critters. Motorized recreation vehicles of any class or type are not permitted for use in the Nature Preserve.

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-4 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.

Mountain Bike Ride, Limestone Canyon
Subscribe to