The IROS Advanced Distance Hike otherwise known as “Sufferfest” by its participants – is designed for experienced hikers who thrive on long days, big climbs, and the satisfaction of pushing physical and mental limits. This hike covers approximately 13 miles with 2,500 feet of elevation gain, traversing some of the most rugged and remote sections of the Irvine Ranch Open Space. This route combines steep ascents, rolling ridgelines, and exposed terrain with panoramic views that make every step worth the effort.

This is not a casual stroll – it’s a test of endurance, pacing, and preparation. Participants should have prior experience with strenuous, half-day or full-day hikes and be comfortable navigating challenging terrain in varying conditions. Self-Sufficiency is Required!

There are no water sources, food stations, or supply drops along this route. Every participant is responsible for carrying all the gear, water, and nutrition they will need for the day. We strongly recommend: Water: Minimum 70 oz per person (more in hot weather) Food/Snacks: High-calorie, easily portable items to sustain 5 hours of hiking (energy bars, trail mix, sandwiches, electrolyte chews) Gear: Closed-toe hiking shoes or boots, sun protection (hat, sunglasses, sunscreen), extra layers, basic first-aid kit, trekking poles (optional but recommended) Under-prepared participants may be denied access to the hike.

Pace & Timing Expect to be on the trail for 5 hours, with extended climbs and limited shade. A steady, sustainable pace is critical. We will take short breaks as needed, but hikers should be able to maintain consistent forward progress throughout the day.

Important Notes This hike is physically demanding and not suitable for beginners. There will be no early exit points – once you commit, you must be prepared to complete the route. Weather conditions can greatly affect difficulty. Hot days will make the climbs especially punishing; cold or wet weather can increase risk and exposure. If you’re ready for a true challenge, breathtaking views, and the camaraderie of fellow “Sufferfest” enthusiasts, join us for the Irvine Ranch Open Space Advanced Distance Hike Series- and earn every mile the hard way. 

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.

Learn more and register here

Ready for a workout? Forget the gym for the day and head outside! Join us for an exhilarating morning fitness hike on the paved Hicks Haul Road in OC Parks’ Irvine Ranch Open Space. This hike allows you to choose between a 3, 6, or 8 mile route, all of which are conducted at the speed of about 3.0 to 3.5 miles per hour. The footing on the asphalt paved road is smoother than dirt roads and single track trails normally found in Limestone Canyon Nature Preserve, but is beginning to show its age with cracks, crevices and an occasional dip. Otherwise, the terrain is smooth, so this is a great walk for anyone who wants a “wilderness experience” without getting dirty! The 6 and 8 mile routes experience two fairly steep ascents and descents. The 3 mile route takes you to the top of Loma Ridge and back down. Along the way, you will have sweeping views of much of Orange County and the Santa Ana Mountains. Various animals, like hawks, deer, and lizards are also frequently seen in this area.

Participants should be confident in their ability to hike 3, 6, or 8 miles at a steady pace. Please come prepared with proper hiking attire, ample water and adequate sun protection. Because of the paved surface, you may wear walking or running shoes instead of hiking boots. For the longer distances, at least 2 quarts of water (64 oz) is recommended. Ages 16 and up.

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

We start our ride through OC Parks’ Irvine Ranch Open Space on the paved Hicks Haul Road, the extension of Jeffrey Rd north of Portola Pkwy. As we warm up on the climb to the top of the road, we enjoy increasingly beautiful views over Irvine. We then follow Loma Ridge to the East, with fantastic vistas of Orange County, the surrounding wildlands, and even Catalina Island on clear days. From Loma Ridge, we descend on a single track to Box Springs which provides year-round water for wildlife like deer.

After the springs, we continue to the Sinks, Orange County’s own “Grand Canyon,” where we enjoy our snacks during a short break. On our way back, we ride along Limestone Ridge, a fun singletrack that leads us towards the Augustine Staging area, enjoying views of Saddleback and Santiago Canyon. From there we will climb back up to Loma Ridge, and then coast back down on the paved Hicks Haul Road to our starting point. 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.

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

Be prepared to experience the beauty and wonder of Weir Canyon, part of OC Parks’ Irvine Ranch Open Space, steeped in history and lore, on this morning equestrian ride. The ride will travel through Weir Canyon, where the trail weaves its way through a beautiful oak woodland inhabited by deer, coyote, bobcat, and many different birds. You will travel the route of the Butterfield Stage and see a monument dedicated to the Mexican ox cart drivers. If time permits, we will climb to the Two Tower vista point to look at distant views. This ride travels on wide trails with several easy to moderate climbs. 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 and distances over asphalt pavement. Please bring water on the ride.

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

Birds are among the most colorful and entertaining forms of wildlife on the Irvine Ranch Natural Landmarks. Bring your binoculars and join us on a slow/medium paced walk in OC Parks’ Limestone Canyon, as we search for resident and visiting birds of the local coastal sage scrub, oak woodland, riparian, and grassland habitats. We will discuss the diverse features of the birds we observe and how they match the season, their habitat and lifestyle. We will travel mostly on ranch roads, usually without shade. Beginners to advanced bird enthusiasts are welcome. Please wear sturdy shoes suitable for hiking and bring water, along with sun protection such as a hat and sunscreen. Bring a small birding field guide if you have one. A few binoculars will be available to borrow.

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-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

Be prepared to experience the beauty and wonder of Weir Canyon, part of OC Parks’ Irvine Ranch Open Space, including the beautiful views from the Overlook Trail.  This ride will travel through Weir Canyon, where the trail weaves its way through a beautiful oak woodland inhabited by deer, coyotes, bobcats, and a variety of native birds. You will travel the route of the Butterfield Stagecoach and see a monument dedicated to the Mexican Ox Cart drivers. We will continue our ride through coastal sage scrub over large rock formations past oak woodlands and up the Overlook Trail. On a clear day, we will be rewarded with sweeping views of the Irvine Ranch Natural Landmarks and more distant views of the Palos Verdes Peninsula, Los Angeles Basin, and Cleveland National Forest.

The participant’s horse must be able to ride 9+ miles with an accumulated elevation gain of 1800 feet.

This ride travels on wide trails and single tracks with several moderate to steeper climbs with a steep switchback descent. Equestrians must have trail riding experience and their own fit and able horse. You will need to transport your horse to the staging area and please be ready to ride at 10:00 am. Owners of unshod horses, please note that footing will include areas of gravel and distances over asphalt pavement. Please bring water for yourself and your horse 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-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

Come enjoy a scenic evening cardio hike in the remote Fremont Canyon Nature Preserve, part of OCParks’ Irvine Ranch Open Space. Our hike climbs steeply from the mouth of Fremont Canyon, past an abandoned coal mine, up to the Fremont Weather Station. After enjoying the view, we’ll turnaround and hike back the same way to our starting point.

This challenging hike involves steep climbs and a 1200’ elevation gain but the rewards are sweeping views of Fremont at sunset. Please arrive 15 minutes early and come prepared with a sturdy pack, water, closed-toe hiking shoes or boots, sunscreen, first aid, and all other supplies to keep you safe and healthy on the trail.

Each participant must carry his or her own day pack and water and be comfortable hiking an average moving pace of 3+ miles per hour. Please make sure you have a minimum of 70oz. (2 quarts) of water. Under prepared participants may be denied access to this program.

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-4 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

Enjoy riding in the wilderness on empty trails? Then join us on a docent-led mountain bike ride that loops through Baker Canyon. The route features expansive views of Silverado and Santiago Canyons, Irvine Lake and the Santa Ana Mountains, as well as the flora and fauna of the Black Star Canyon Wilderness Park. This is a great opportunity to enjoy this seldom visited wilderness area of Orange County!

This ride is designed for the experienced beginner to intermediate rider who is physically fit and can climb moderate climbs of up to one mile and is comfortable riding single track trails with some short/beginner technical sections. The ride is on largely non-technical single track trails and the fire roads that interconnect them. The ride will regroup and rest as needed and an opportunity will be provided for a snack break.

Please note, the ride is approximately 10 miles long with 1500 feet of elevation gain. The route has climbs with some moderately steep sections.

This activity originates and ends at the Baker Canyon Staging Area and takes place in OC Parks’ Black Star Canyon Wilderness Park.

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. Electric Mountain Bikes of any class or type are not permitted.

Learn more and register here

You will enjoy a gorgeous sunset with panoramic views of Orange County while hiking in OC Parks’ Irvine Ranch Open Space on the paved Hicks Haul Road. This hike travels 6 miles, out and back crossing over Loma Ridge. This is the perfect activity for you to get your work-out in and view the sunset. The hike is conducted at an average pace of 3 miles per hour, but you may travel a bit faster or slower, at a walk, run, or jog depending on your comfort level. 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 Sunday morning in OC Parks’ Irvine Ranch Open Space for a fitness-focused hike on the Hicks Haul Road, West Loma and Shoestring trails in Limestone Canyon. Hikers will enjoy wonderful views and a panoramic overview of Orange County. The hike starts at Hicks Haul Road staging area and will cover a distance of 8.5 miles, about 5 miles of the hike is on paved surface and rest on trails. Participants are expected to hike close to 3 miles per hour and come prepared with closed toe hiking boots or shoes, water, trail snacks, sunscreen, hat, day pack or fanny pack, and any other necessary equipment or supplies you might need to keep you safe on this hike.

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-4 activity on the land. To learn more about the staging areas and activity locations, please visit our Staging Areas Playlist page.

Learn more and register here