Join us for a look into the park’s landscapes during the past 25 million years. We will see evidence of ancient volcanic activity, shifting sea floor sands, clam fossils telling us of a shallow bay, ancient faults and earthquakes, recent landslides, and formation of our sandstone caves.

For more information and to sign up, CLICK HERE.

Join OC Parks at Heritage Hill Historical Park this fall for the return of Fall-O-Ween! Tour the decorated historical grounds during special park hours and take your picture at a variety of fall and Halloween-themed photo opportunities.

Try to find your way through the straw maze and complete a scavenger hunt for ghoulish goodies at this free, family-friendly event.

Costumes are encouraged and pets are welcome on leashes no longer than 6 feet. Be sure to grab your cameras!

Enjoy miles of lush oak studded canyons, fascinating rock formations and sweeping views from the Overlook Trail in the tranquility of the Weir Canyon back country, part of OCParks’ Irvine Ranch Open Space. On a clear day we’ll be rewarded with glorious views of the San Gabriel and Santa Ana mountains. This is a FAST-paced fitness hike, and features an 1800 ft accumulated elevation gain. There are multiple steep climbs and steep descents. Please make sure you are in excellent physical condition! You must be able to hike uphill at an average pace of 3 mph without stopping. A backpack and water are required. Please bring snacks, sun screen, hat and wear sturdy closed-toe shoes.

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.

Join Mile Square Regional Park staff and volunteers in enhancing the Nature Area habitat for local wildlife. Activities may include non-native plant removal, planting natives, watering, trash cleanup, and Butterfly Garden maintenance.

No experience is necessary; please bring a hat, sunscreen, snacks, water, wear closed toe shoes and a long sleeve shirt is recommended. Tools are provided. Please arrive on time, as work will begin promptly at 8 am.

Please note, this is a weekly reoccurring activity and space is limited.

• Space is limited and pre-registration is required.
• Minors ages 16 and younger must have a legal guardian present at all times.
• Rain or heat advisories cancel the event.

Mile Square Nature Area Parking Map

Join Laguna Canyon Foundation volunteer mountain bike trail guides for either Intro or Intermediate Mountain Biking. Both meet at same location and time.

Intro to Mountain Biking
8:30 AM — 11:30 AM
Join Laguna Canyon Foundation volunteer mountain bike trail guides on this beautiful 8-mile bike ride (400-ft. elevation gain) on uneven terrain. Learn mountain biking basics and trail etiquette while enjoying the canyon views. Please come prepared with a bike suitable for off-pavement riding, sturdy shoes, helmet, gloves, water and snack.

Sign up for Intro, For more information and to sign up, CLICK HERE.

Intermediate Mountain Biking
8:30 AM — 10:30 AM
Catch beautiful canyon views on this 10-mile ride over steep and uneven terrain (1,600-ft elevation gain) with Laguna Canyon Foundation volunteer mountain bike trail guides. This is for INTERMEDIATE riders with mountain biking experience. Appropriate mountain biking equipment required. Must have helmet, gloves, hydration; a snack is strongly suggested. Also, be prepared for varied weather out in the canyons. This bike ride is not for beginners.

Sign up for Intermediate, For more information and to sign up, CLICK HERE.

Come chat with a Civil War living historian at the cannon in Irvine Regional Park. The volunteer will share the history of the 1853 Howitzer cannon and how it came to be at its current location. Hear recounts of other historical elements found in and around Irvine Regional Park’s long history.

The volunteer may take periodic breaks. Check with the Nature Center on future Civil War reenactor visits!

You can find the Civil War living historian located at the cannon and Spanish-American War Veterans monument at the lake, near the snack stand and boat house, between Parking Lots U and T.

For further questions, please contact Resource Specialist Kelley Brugmann at kelley.brugmann@ocparks.com and 714-973-6625

A slow-paced beginner mountain bike ride for adults in Limestone Canyon, part of OCParks’ Irvine Ranch Open Space, through sycamores, oaks, and habitat native to California. The route takes us to The Sinks, Orange County’s own mini “Grand Canyon.” Along the way, we will stop and talk about the local habitat, and hope to see some of our local native animals and raptors. For mountain bikers with a minimum of six months of trail experience who would like to join IRC-certified volunteers on an 8 – 9 mile ride with 400 – 800 feet of elevation gain.  This ride is for adult riders only. Allow up to 2.5 hours of riding time.

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.

Join OC Parks at Heritage Hill Historical Park this fall for the return of Fall-O-Ween! Tour the decorated historical grounds during special park hours and take your picture at a variety of fall and Halloween-themed photo opportunities.

Try to find your way through the straw maze and complete a scavenger hunt for ghoulish goodies at this free, family-friendly event.

Costumes are encouraged and pets are welcome on leashes no longer than 6 feet. Be sure to grab your cameras!

Discover the hidden canyons and trails found in Round Canyon, part of OCParks’ Irvine Ranch Open Space. These seldom hiked trails offer fantastic vista views, wildflowers, secluded oasis of oaks, and rising rocky outcrops. Come take a stroll along the trails to discover the hidden gems of Orange County. We will listen to tales how the geology was formed underfoot to tales of the plants and animals that call these protected habitats home. Please wear comfortable clothes and shoes for our hike as well as bring proper sun protection and water.

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.

Join us every Monday night in OCParks’ 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 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!

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.

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 OCParks’ 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.

Reviewing the 1-through-5 Difficulty Ratings will help you evaluate your readiness to participate in this level-3/4 activity on the land. Please visit our FAQ page for answers to activity specific questions you may have prior to registering.

Our eight-legged friends are truly amazing arachnids! Discover the wonders of their little lives and the big impacts they have in nature. Hear a fun tale about a spinning spider and create your own arachnid craft to take home.

This fun program is for ages 2 – 6 years. Space is limited; parents must register themselves and each child. Program is free though there is a Park Entrance Fee per entry vehicle. For questions, please contact Resource Specialist, Kelley.Brugmann@ocparks.com at 714-973-6625.

Stroll through the park searching high and low for our flittering friends. Listen for their sweet song and hear fun associations to help you remember these birds. Program is geared for all levels, though is focused for beginner-intermediate level birder. Bring your binoculars, sun protection, comfortable shoes, and an eye for spotting our feathered friends!

Program is free though there is a Park Entrance Fee per entry vehicle. For questions, please contact Resource Specialist, Kelley.Brugmann@ocparks.com at 714-973-6625.

Join us every Wednesday night in OCParks’ 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!

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.

This week in OCParks’ Irvine Ranch Open Space, we’ll hike in the remote Fremont Canyon. The hike is just under 6 miles and includes a steep hill. We will hike from the mouth of Fremont Canyon, past a historic coal mine, to the Fremont Weather Station. After enjoying a spectacular view, we will hike back the same way to our starting point. Please bring water, a trail snack, sun screen, hat, and any other necessary equipment to keep you safe on the trail and wear sturdy, closed-toe hiking shoes. Participants must be able to hike 6 miles with an elevation gain of 1200 feet at an average moving rate of 3 miles per hour. Each hiker must carry his/her own water and supplies.

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.

Please be aware this is a Fitness Hike and not for beginners; the pace is approximately a 19-minute mile. Raise your heart rate and your spirits on this difficult, strenuous, and fast-paced, 6.6-mile hike (1,100-ft. elevation gain) over very steep, uneven terrain with Laguna Canyon Foundation volunteers.

For more information and to sign up, CLICK HERE.

Around 25,000 plants have been installed at our Big Canyon restoration site, and we would love your help protecting the new plantings from invasive plants. Invasive plants pose a huge threat to displacing native plant communities and wildlife at the Bay, second only to habitat loss. By removing invasive weeds, we will ensure the Big Canyon project site thrives with native plants for years to come. No prior plant ID/weeding experience necessary.

Minors must have a legal guardian present at all times.

To register, go to: RestoreBigCanyon.eventbrite.com

Interested in bringing out a large group of 15 or more? Please contact Zachery Flores at zachery.flores@newportbay.org for more information on how to sign up.

Time & Location
We will meet at 9am at the project site entrance. A map with directions will be included in your confirmation email following registration. From the parking location, the project site is a short 5-minute walk into the canyon. NOTE: There are no restrooms at this location.

What to Bring/Wear
Be sure to bring sunscreen, a hat, and plenty of water. We also recommend wearing breathable clothing that you don’t mind getting dirty. Hand tools, shovels, and gloves will be provided. All volunteers not yet fully vaccinated must wear a face mask while on the project site. Face masks are optional for fully vaccinated volunteers.