Join the Friends of Princeton Open Space (FOPOS) for a volunteer stewardship session on Saturday, March 22nd, 2025 from 10AM - 12PM!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecosystem restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely efforts and maintaining our natural lands.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer stewardship session on Wednesday, March 19th 1 PM - 3 PM!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecological restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve.

Spring is almost here, and it’s time for our March clean-up! Volunteers will head out to the forest restoration site to remove invasive species like wineberry, multiflora rose, and English ivy. These plants are crowding out the native trees and shrubs we’ve worked hard to plant, including paw paw, persimmon, and flowering dogwood. If you’re looking for a fun way to spend time outdoors and make a real difference, this is the perfect chance to get involved and help protect our local ecosystem.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a volunteer stewardship session on Saturday, March 15th, 2025!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecosystem restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely efforts and maintaining our natural lands

We have two volunteer sessions:

Session 1: 10 AM - 12 PM
Session 2: 1 PM - 3 PM

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer stewardship session on Wednesday, March 12th 10 AM - 12 PM!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecological restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer stewardship session on Friday, March 7th 1 PM - 3 PM!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecological restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer stewardship session on Thursday, February 27th 1 PM - 3 PM!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecological restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve.

Sign up online.

Join us for our February Nature Walk through the Billy Johnson Mountain Lakes Nature Preserve.

Led by the Friends of Princeton Open Space stewardship team, this guided walk will offer a chance to explore the quiet, wintery landscape and discover the unique beauty of the preserve during the colder months.

As we walk, we’ll focus on how the local wildlife adapts to winter conditions, how plant life responds to the season, and the role the preserve plays in supporting biodiversity year-round. Our stewardship team will also share insights into the history of the preserve and the ongoing land stewardship efforts that help protect this special place for future generations.

Photo Credit: Snowy Path by Kristina Corvin

Sign up for our February Nature Walk on Eventbrite

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer stewardship session on Wednesday, February 19th 1 PM - 3 PM!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecological restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a volunteer stewardship session on Saturday, February 15th, 2024!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecosystem restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely efforts and maintaining our natural lands

We have two volunteer sessions:

Session 1: 10 AM - 12 PM
Session 2: 1 PM - 3 PM

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a seed sowing event on Saturday, February 8th from 10AM - 12PM.

Dreaming of spring? Join us at the beautiful Mountain Lakes House for a seed sowing event. Help our stewardship team sow native seeds for the spring 2025 season!

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a volunteer stewardship session on Saturday, February 1st, 2024!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecosystem restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely efforts and maintaining our natural lands

We have two volunteer sessions:

Session 1: 10 AM - 12 PM
Session 2: 1 PM - 3 PM

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer land stewardship session on Wednesday, January 15th from 1PM - 3PM.

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecological restoration work and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve.

Sign up online.

Meeting Location: Mountain Lakes House Parking lot, 57 Mountain Ave, Princeton NJ, 08540. Be sure to drive down the long paved driveway entrance to the Billy Johnson Mountain Lakes Nature Preserve, marked by a series of black mail boxes. The gravel parking lot is on your left about a 1/2 mile down the driveway.

Sign up online.

Start the year with a peaceful winter nature walk through the Billy Johnson Mountain Lakes Nature Preserve.

Led by our stewardship team, this guided walk will offer a chance to explore the quiet, wintery landscape and discover the unique beauty of the preserve during the colder months.

As we walk, we’ll focus on how the local wildlife adapts to winter conditions, how plant life responds to the season, and the role the preserve plays in supporting biodiversity year-round. Our stewardship team will also share insights into the history of the preserve and the ongoing land stewardship efforts that help protect this special place for future generations.

This is a great opportunity to enjoy the calm of the winter woods, get some fresh air, and start the year with a deeper connection to nature.

Be sure to wear sturdy, weather-appropriate footwear and bring a pair of binoculars if you’d like to spot winter birds or other wildlife.

Photo Credit: Sparrow by Melissa Dzik

Sign up for our January Nature Walk on Eventbrite

Join FOPOS for a Day of Service on MLK Day 2025! During this session, volunteers will work with FOPOS's stewardship team to battle invasive plant outbreaks at the Preserve. We will also work to free large established trees from the grip of invasive vines. Participants will gain skills in plant identification and learn about some of the pressures New Jersey's forests face.

We have two session times: 10am-12pm and 1pm-3pm.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a seed sowing event on Saturday, January 18th from 10AM - 12PM.

Dreaming of spring? Join us at the beautiful Mountain Lakes House for a seed sowing event. Help our stewardship team sow native seeds for the spring 2025 season!

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer land stewardship session on Wednesday, January 15th from 1PM - 3PM.

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecological restoration work and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve.

Meeting Location: Mountain Lakes House Parking lot, 57 Mountain Ave, Princeton NJ, 08540. Be sure to drive down the long paved driveway entrance to the Billy Johnson Mountain Lakes Nature Preserve, marked by a series of black mail boxes. The gravel parking lot is on your left about a 1/2 mile down the driveway.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) and South Jersey Wildlife Tours for a guided Woodpecker Walk on Saturday, November 23rd at 9:30am. We will explore the trails of the Billy Johnson Mountain Lakes Nature Preserve in search of the fascinating woodpeckers that call New Jersey home.

Sign up on Eventbrite.

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer stewardship session on Wednesday, December 18th 1PM - 3 PM!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform riparian and forest restoration, invasive species removal, and plant native species in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely fall cleanup and planting efforts.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a volunteer stewardship session on Saturday, December 14th, 2024!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform ecosystem restoration and invasive species removal in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely efforts and maintaining our natural lands for the winter months ahead.

We have two volunteer sessions:

Session 1: 10 AM - 12 PM
Session 2: 1 PM - 3 PM

Sign up online.

Stop in any time at our Holiday Open House. Enjoy a warm drink, holiday treats, and our Perspectives on Preservation photography exhibition. Learn more about the Friends of Princeton Open Space and while you're here, take a stroll outside to see our beautifully decorated Christmas tree and gather with community members to celebrate the season.

Free and open to all. We kindly ask for your RSVP.

Stop in any time at our Holiday Open House. Enjoy a warm drink, holiday treats, and our Perspectives on Preservation photography exhibition. Learn more about the Friends of Princeton Open Space and while you're here, take a stroll outside to see our beautifully decorated Christmas tree and gather with community members to celebrate the season.

Free and open to all. We kindly ask for your RSVP.

Join us for our December Nature Walk at the Billy Johnson Mountain Lakes Nature Preserve. Led by Anna Corichi, Friends of Princeton Open Space's Director of Natural Resources and Stewardship, we'll observe the great diversity of life at the Preserve and learn more about the work that is being done by our stewardship and trails teams. After the walk, you are invited to warm up inside at our Holiday Open House!

Sign up for our December Nature Walk on Eventbrite

Please join Friends of Princeton Open Space at the Mountain Lakes House for the opening reception of our annual Perspectives on Preservation Photography Exhibition, featuring selected photographs from our 2024 photo contest, as well as photographs of the Mountain Lakes Open Space Area by Frank Sauer.

Free and open to all. We kindly ask for your RSVP.

Join the Friends of Princeton Open Space (FOPOS) and South Jersey Wildlife Tours for a guided Woodpecker Walk on Saturday, November 23rd at 9:30am. We will explore the trails of the Billy Johnson Mountain Lakes Nature Preserve in search of the fascinating woodpeckers that call New Jersey home.

Sign up on Eventbrite.

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer stewardship session on Wednesday, November 20th 10:00am-12:00pm!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform riparian and forest restoration, invasive species removal, and plant native species in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely fall cleanup and planting efforts.

Sign up online.

Join us for a fall nature walk around the lake at the Billy Johnson Mountain Lakes Nature Preserve. Led by Anna Corichi, Friends of Princeton Open Space's Director of Natural Resources and Stewardship, we'll explore the beauty of the fall season and witness the wonders of nature preparing for winter.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a volunteer stewardship session on Saturday, November 9th, 2024 from 10AM - 12PM!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform riparian and forest restoration, invasive species removal, and plant native species in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely fall cleanup and planting efforts.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) for a weekday volunteer stewardship session on Wednesday, November 6th 1PM - 3 PM!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform riparian and forest restoration, invasive species removal, and plant native species in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely fall cleanup and planting efforts.

Sign up online.

Join the Friends of Princeton Open Space (FOPOS) and South Jersey Wildlife Tours for a guided Eastern Screech Owl Walk at dusk on Sunday, October 27th at 7:30pm.

Did you know that Eastern Screech Owls are one of the most common owl species in North America? Odds are you have one of these nocturnal neighbors mere miles (or less!) from your doorstep. During this experience, we will walk the trails at the Billy Johnson Mountain Lakes Nature Preserve in Princeton and listen and look for Eastern Screech Owls, learning much more about them along the way.

Space is limited to 20 participants; be sure to sign up in advance. Please note that this event is geared towards adults as it begins at 7:30 PM.

Cost: Adults are $15 each and kids under 10 are free.

Please note that Screech Owl sightings are not guaranteed. We do have high owl activity at the preserve but you never know how the night will go.

Sign up on Eventbrite.

Join the Friends of Princeton Open Space (FOPOS) for a volunteer stewardship session on Saturday, October 26th, 2024!

Volunteers will work under the guidance of the FOPOS stewardship staff to perform riparian and forest restoration, invasive species removal, and plant native species in the Billy Johnson Mountain Lakes Nature Preserve. We will focus on timely fall cleanup and planting efforts.

We have two volunteer sessions:

Session 1: 10 AM - 12 PM
Session 2: 1 PM - 3 PM

Sign up online.