Prince William Conservation Alliance
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2017 Butterfly Count - Manassas Circle
Rescheduled due to rain - Sunday, August 6, beginning at 10 am

Volunteer! Wildlife Garden at Merrimac Farm WMA
Saturday, Aug 26, 9am to noon

Butterfly Walk at Merrimac Farm WMA
Sunday, September 17, 1-3pm

Insect Survey at Merrimac Farm WMA
August 14, August 28

Leesylvania State Park Living Shoreline: Protecting Potomac River Shorelines
September 10, 2pm

PWCA Open House - Honoring Tom Smith, PWC Solid Waste Division Chief
Wednesday, September 20, 5:30pm

The Occoquan Greenway Trail - Ten Year Anniversary Hike!
October 28, 10am

Bird Walk at Merrimac Farm WMA
Last Sunday of every month beginning at 8:00am... except for December, when we host the Nokesville Christmas Bird Count.

Most of our programs are free of change thanks to the generous support from people like you!

Click here to read more about us. Click here to donate and support local opportunities.

View our local nature calendar here.

Questions? Contact PWCA at 703.490.5200,

2017 Butterfly Count - Manassas Circle

When: Saturday, July 29 rained out - rescheduled to Sunday, August 6, beginning at 10am

RSVP Required to alliance@, 703.499.4954. You'll receive the meeting location for your survey team.

MonarchHelp us count butterflies for the Annual 4th of July Butterfly Count and learn more about butterfly populations close to home.

This count is part of a nationwide program led by the North American Butterfly Association (NABA), which compiles information about butterfly populations and distribution that's used to study the effects of climate and habitat change on North American butterflies.

“Every single day there are fewer butterflies in the United States than there were the day before. You don’t have to be a genius to figure it out,” said geneticist and NABA president Jeffrey Glassberg.

Here in Prince William on July 29, we'll form teams and see how many butterflies we can find within our 113,000 acre count circle (centered on Manassas Airport). To view our survey area on Google Earth, use the coordinates 38.724270, -77.500466 as the center point for a circle with a 7.5 mile radius.

We submit our compiled results to NABA's national database for butterflies. Everyone is welcome. We are also seeking tips on specific areas to survey, notably areas with flowers. Please email us if you have ideas.

Wildlife Garden Workday

When:Saturday, Aug 26, 9am to noon

Where: Merrimac Farm Wildlife Management Area, 15014 Deepwood Lane, Nokesville 20181, directions

Zebra Swallowtail on ButterflyweedThanks to volunteer support, we created an area at Merrimac Farm WMA where people and the environment can come together as one. It's a great area to watch wildlife, learn about native plants and pollinators, and get ideas for your own backyard.

We need help to keep nonnative invasive plants in check to maintain high quality habitat. Even if you can come just once, your help makes a big difference. Wear long pants, sturdy shoes, and long socks.

Questions and RSVP (appreciated) to alliance@ or 703-499-4954.

Read more about Merrimac Farm Wildlife Management Area HERE.

Insect Survey at Merrimac Farm WMA

When: 4:00 to 6:00pm on Monday, August 28

Where: Please RSVP to alliance@ for the meeting location.

Tulip Tree SilkmothJoin us as we search for butterflies, dragonflies and other important pollinators.

Help us learn more about wildlife diversity, habitats at Merrimac Farm, meet new friends, and explore the great outdoors.

This is a regularly scheduled survey that occurs every other Thursday through mid September.


PWCA Open House - Honoring Tom Smith, PWC Landfill Chief

When:Wednesday, September 20, 5:30 to 7:00pm

Where: PWCA office, 2241F Tackett's Mill Drive, Woodbridge

LandfillFollowing many years of service to Prince William citizens, Solid Waste Division Chief Tom Smith will soon retire.

Tom leaves a legacy of improvements that have advanced the environmental sustainability of our landfill. Thanks to his steady march forward, the County has established recycling, active yard waste composting, and methane gas programs, to name a few. Learn more about Tom's achievements at our Open House.

Please join us for a drinks, appetizers, and a toast to Tom Smith! Our Open House is free of charge, everyone is welcome. For more information, contact us at or 703-499-4954.

Butterfly Walk at Merrimac Farm WMA

When: Sunday, Sept 17, 1-3pm

Where: Meet at Merrimac Farm, Stone House, 15014 Deepwood Lane, Nokesville

American SnoutJoin us as we search for butterflies! Learn how to identify butterflies and habitat diversity, meet new friends, and explore the great outdoors.

No experience needed, families welcome. RSVP appreciated to

Leesylvania State Park Living Shoreline: Protecting Potomac River Shorelines

When: Sunday Sept 10, at 2pm

Where: Meet in the main (last) parking lot Leesylvania State Park, 2001 Daniel K. Ludwig Drive, Woodbridge

RSVP required to alliance@ or 703.499.4954

Leesylvania State ParkJoin us for a walk along a living shoreline at Leesylvania State Park led by ecologist Charles Smith and project designer Tom Dombrowski.

As sea levels rise, erosion of our Potomac River shoreline will increasingly threaten wetlands and wildlife habitats, and reduce the abundance of key bird and other species.

A variety of approaches to protect these important resources are available, ranging from hard fixes to investments to enhance natural areas.

Living shorelines use natural materials and vegetation to reduce erosion and provide habitat. Traditional shoreline protection uses rock and man-made materials that often fail, are unattractive and do not support wildlife.

By mixing traditional materials with native plants, biodegradable matting and wood, attractive, stable shorelines can be created that protect wetlands and host numerous animal species.

Learn how the living shoreline at Leesylvania State Park was designed and functions, and observe the many benefits it provides to local communities and the Chesapeake Bay.

The Occoquan Greenway Trail - Ten Year Anniversary Hike!

When: Sat, Oct 28, 2017 at 10am

Where: Meet in the parking lot of Lake Ridge Park, 12373 Cotton Mill Road, directions

RSVP required to alliance@ or 703.499.4954
Join us for a fun day outside, get a little exercise, meet new friends, and support the expansion of trails in Prince William.

Phoebe by Julia FlanaganSponsored by Prince William Conservation Alliance and Prince William Streams and Trails Coalition

Ten years ago we led the first hike down the Occoquan Greenway Trail from McCoart Government Center to the Town of Occoquan, beginning a community effort to improve conditions and open the trail to the public.

Today, about 2.4 miles of contiguous trail is available for hiking, from Lake Ridge Park to Cotton Mill Drive.  

On October 28, we will hike about 7 miles, beginning at Lake Ridge Park and ending in the Town of Occoquan about three hours later. Transportation back to your car at Lake Ridge Park is provided.

The trail surfaces include well-established natural surfaces, cleared paths in the woods, blacktop paths, sidewalks along streets and fair-weather stream crossings, which may include some steep banks.

Please dress accordingly – we recommend long pants, sturdy hiking shoes, a hat and long socks. Bring a bag lunch, plenty of water, binoculars, and a camera to capture the beautiful scenery along the way! Click here to read about previous hikes.

Bird Walks at Merrimac Farm

When: On the last Sunday of every month at 8am

Where: Meet at Merrimac Farm, Stone House, 15014 Deepwood Lane, Nokesville

Phoebe by Julia FlanaganWe'll look for birds as we travel through the uplands to the edge of the floodplain, covering a variety of habitats, including open fields and woodland edges. Everyone is welcome.

Dress for the weather, bring binoculars and cameras. More info and RSVP (appreciated) to PWCA , 703.499.4954 or

View the bird list for Merrimac Farm HERE.


The best time to plant a tree was 20 years ago. The second best time is today.
Prince William Conservation Alliance is a nonprofit watershed organization serving Prince William and surrounding communities. We're working to explore, enjoy and protect our natural areas, and increase community involvement in stewardship opportunities.