Activities and Programs

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.

Join us for an amazing distance hike from remote Fremont Canyon to the oak woodlands of Weir Canyon. Shortly after leaving Irvine Regional Park, this hike climbs steeply from the mouth of Fremont Canyon and passes an abandoned coal mine. We continue through Upper Blind Canyon, up to a scenic overlook and then drop down to Weir Canyon as we wind our way back to Irvine Regional Park. Distance is up to 14 miles and is designed for advanced hikers. Participants must be physically fit and have distance hiking experience.

**Due to trail closures, this hike is being rerouted. It will not be the full 16 mile loop but an out and back to “Mini Moab”. The hike will be shortened to 14 miles with 2900 feet of elevation gain.**

Join us for an extremely challenging and strenuous hiking adventure in the scenic Fremont Canyon Wilderness Area. This 16-mile loop hike is for experienced, physically fit distance hikers. The hike is on fire/SCE dirt roads with numerous significantly steep, unrelenting climbs and descents. We hike the entire rim of Fremont Canyon, passing by an abandoned coal mine, the Fremont Weather Station and the remnants of a rare stand of Tecate cypress. Along the way we’ll have sweeping views of Orange County, the Santa Ana Mountains and surrounding mountain ranges.

Come enjoy an early morning hike in Fremont Canyon Nature Preserve, part of OC Parks’ 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 where winds have been clocked at up to 100 mph. After enjoying the view, we’ll hike back the same way to our starting point. This hike involves steep hills and a 1200’ elevation change but the rewards are panoramic views of Orange County, the Santa Ana Mountains and surrounding areas as well as possible wildlife sightings. Please arrive 15 minutes early; the entrance gate will be shut and locked 5 minutes before start of the activity. Be sure to 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.

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.

The Irvine Ranch Open Space Ultra Distance, series 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 18 miles with 3,400 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 7 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 7 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 Ultra Distance Hike — and earn every mile the hard way.

Join us for an extremely challenging and strenuous hiking adventure in the scenic Fremont Canyon Wilderness Area. This 16-mile loop hike is for experienced, physically fit distance hikers. The hike is on fire/SCE dirt roads with numerous significantly steep, unrelenting climbs and descents. We hike the entire rim of Fremont Canyon, passing by an abandoned coal mine, the Fremont Weather Station and the remnants of a rare stand of Tecate cypress. Along the way we’ll have sweeping views of Orange County, the Santa Ana Mountains and surrounding mountain ranges.

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. Climb challenging State Spur to Cathedral Rock, and then descend into Fremont Canyon while passing some of Orange County’s most spectacular geological formations. The ride continues out to Mini-Moab and then over to Sierra Peak, passing the Tecate Cypress forest, then past Sierra Peak, and over to the last descent down through historic Black Star Canyon. Motorized recreation vehicles of any class or type are not permitted for use in the Nature Preserve. 

Come bring your horse and join us on the sage-scented trail up and down gentle hills. We will start from Irvine Park and proceed on the Irvine Regional Park Horseshoe Loop to Waterworks trail that will take us under the towering overpass of the 241 Toll Road. We will see the foot of the Irvine Lake Dam and catch a glimpse of the heart of Fremont Canyon. We will pass the site of an enormous coal pile left by miners of yesteryear and then return to the park.

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.