Sunday, January 21, 2024

Winter Stream Clean-ups

There are plenty of opportunities to explore lower Four Mile Run and help keep it clean this winter. Come out for one of our land-based clean-ups in Alexandria and Arlington.

  • Saturday, January 27, 9:30am at Long Branch Creek in Troy Park, Arlington
  • Sunday, February 11, 3pm, trail/shoreline starting from South Eads Street, Arlington
  • Presidents Day Monday, February 19, 9:30am, Alexandria shoreline near Mount Vernon Avenue
  • Saturday, March 2, 8:30am park/shoreline near Commonwealth Avenue, Alexandria
  • Saturday, March 16, 8:30am, Arlington shoreline near Mount Vernon Avenue
  • Sunday, March 24, 3pm at Sunnyside tributary, west side of Four Mile Run Park
Details on these and other upcoming events are on the events calendar. Sign-ups open 2-3 weeks prior to each clean-up event.


Friday, January 19, 2024

Support Accessible Paddling Access with Comments to VMRC

Our accessible kayak/canoe launch project continues to move forward, and the permit request with the Virginia Marine Resources Commission is now open for public comment until Friday, February 2. Please consider submitting a comment in support of this needed public amenity!

Comments can be submitted at the VMRC website -- be sure to reference project # 20232538.

Monday, December 11, 2023

Nature's Engineering Project at Hume Spring

If you've walked the Wetland Trail in the last month or so, you may have noticed an ever-increasing number of fresh-cut tree stumps near the water's edge, particularly in the last month. The construction project currently underway: a beaver dam, visible at low tide, being erected just below the trail bridge at the mouth of Hume Spring. The North American beaver (Castor canadensis) is an important ecosystem engineer, more commonly associated with dams, ponds, and lodges on flowing rivers, but also known to build dams in tidal freshwater settings, as we see at Four Mile Run Park. And they have been making fast progress, well deserving of their reputation for being "busy beavers." The dam is now backing water up the Hume Spring tributary as intended, as can be seen from the photo at right (photo courtesy of Russ Bailey).

Over the past few years, while the wildlife cameras we've installed in the wetland have captured photos of their nighttime activity, we don't yet see evidence that beavers are making the park a permanent home, though they probably have a lodge somewhere nearby. Very likely, the purpose of the dam is to make it easier, safer, and faster for them to access the wetland at low tide to support their diet of twigs, leaves, tree bark, and other plant material. Beavers are slower and more vulnerable on land, but they are fast swimmers, so they benefit from backing up water where, at low tide levels, the stream channel would otherwise be an exposed mud flat.

There may be benefits for other members of the ecosystem. Although there aren't many studies of the impacts of beaver dams in tidal freshwater, some research has shown changes in vegetation composition and increased fish abundance upstream of these tidal dams. And the tree chomping is more and more apparent. Fascinating changes happening at Four Mile Run -- stay tuned!

Tuesday, November 14, 2023

Kayak Launch Project Receives Additional $148K in Grant Funding

14 November 2023


The Alexandria-based organization will establish the DC metro area’s first fully-accessible public access launch point to the Potomac River

Alexandria, VA — The Four Mile Run Conservatory Foundation, an organization committed to promoting nature, culture, and community at lower Four Mile Run in Northern Virginia, has been awarded two grants totaling $147,900 toward construction of a public water access point meeting the standards of the Americans with Disabilities Act (ADA), suitable for launching kayaks, canoes, and other human-powered watercraft, at the tidal portion of Four Mile Run, a Potomac River tributary. The launch will become part of the City of Alexandria’s 49-acre Four Mile Run Park, and it will be the first of its kind in the DC metro area, featuring a raised boardwalk ramp and gangway with ADA-compliant slopes, a wheelchair transfer platform, and a roller water entry/exit ramp, providing increased safety while launching and landing, particularly helpful for unassisted or novice paddlers.

The recent awards are through the National Park Service Chesapeake Gateways Office and the Chesapeake WILD program of the US Fish and Wildlife Service and the National Fish and Wildlife Foundation (NFWF). Together, the two grant awards bring the total funding raised toward the project to $482,714, approaching the overall fundraising goal of $500,000.

“In providing free public access to Four Mile Run and the Potomac, the project will provide residents and visitors an outstanding opportunity for healthy recreation,” said Kurt Moser, president of the Four Mile Run Conservatory Foundation. “We are pleased to receive these grant awards to enable more frequent and more equitable access to nearby nature and the upper reaches of the nation’s largest estuary, the Chesapeake Bay.”
The National Park Service Chesapeake Gateways Office offers competitive grant opportunities to advance the Chesapeake Bay Initiative Act of 1998 within the full 41-million-acre Chesapeake Bay watershed. Chesapeake Gateways grants bring out familiar, untold, under-appreciated, or yet to be uncovered narratives and promote resilient communities and landscapes through tourism, sustainability, conservation, and local economies throughout the Chesapeake Bay watershed.

The Chesapeake WILD program was established to support collaborative conservation in the watershed and provide grant funding for community-driven projects that align with five interrelated focal areas for sustaining the health of the watershed and its inhabitants into the future: conserving and restoring imperiled fish and wildlife habitats; enhancing climate resilience and readiness; building community partnerships and conservation capacity, including in vulnerable communities; increasing equitable public access for recreation and human connections with nature; and improving water quality. The US Fish and Wildlife Service partners with NFWF to deliver the Chesapeake WILD grant program as part of the foundation’s broader Chesapeake Bay Stewardship Fund, a portfolio of competitive grant programs helping to restore and protect the Chesapeake Bay watershed.

Additional information on the project, including current project status and documentation of environmental impacts, is available at

About the Four Mile Run Conservatory Foundation

The Four Mile Run Conservatory Foundation is a 501(c)(3) non-profit corporation and volunteer organization formed in 2016, with a mission to promote nature, culture, and community at lower Four Mile Run through restoration, advocacy, recreation, and education. Each year, hundreds of volunteers participate in land- and kayak-based litter clean-ups, native tree/shrub planting, invasive species removal, community science, and outdoor learning and exploration programs for youth. Visit at, on Facebook at, and on Instagram @4MRconservatory.

About the National Park Service Chesapeake Gateways

Established by Congress in 1998, NPS Chesapeake Gateways is a partnership network and community assistance program. Headquartered in Annapolis, Maryland, the office serves the full 41-million-acre Chesapeake Bay watershed, providing authentic Chesapeake experiences for 21st Century communities and visitors.

About the National Fish and Wildlife Foundation

Chartered by Congress in 1984, the National Fish and Wildlife Foundation protects and restores the nation’s fish, wildlife, plants and habitats. Working with federal, corporate and individual partners, NFWF has funded more than 6,000 organizations and generated a total conservation impact of $8.1 billion.


Tuesday, October 31, 2023

Final Kayak Clean-ups for 2023

This fall we've hosted kayak clean-ups every weekend, and the last ones for the season are happening in November. Join us for beautiful fall days on the water, and help us keep Four Mile Run trash-free!

Sign-ups are open for all dates. Register HERE.

  • Saturday, November 4, 3-6pm
  • Sunday, November 12, 10am-1pm
  • Saturday, November 18, noon-3pm 

Kayaks and all related equipment, snacks, water, and good company are provided!