Irvine Ranch Open Space Advanced Distance Hike: Fremont, Weir, & Blind Canyons

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.