From Flush to Four Mile Run: Inside Arlington’s Water Pollution Control Plant

Text and images by Laura Gilmore, except as noted. Arlington’s Water Pollution Control Plant’s core mission involves protecting downstream ecosystems. (Image captured near the plant’s outfall into Four Mile Run.) ARMN members exploring the Arlington Water Pollution Control Plant during their March tour. Early each morning, millions of gallons of wastewater begin an unseen journeyContinueContinue reading “From Flush to Four Mile Run: Inside Arlington’s Water Pollution Control Plant”

Pools, Frogs, and Salamanders: A Spring Night at the Outdoor Lab

Text and photos by Laura Gilmore (except as noted) ARMN member, Barbara Saffir, brought a cake showcasing a photograph she took and digitally altered to wish everyone a “Happy Salamander Season!” On a cool evening in early March that had begun to feel more like spring than winter, 25 Arlington Regional Master Naturalists (ARMN) gatheredContinueContinue reading “Pools, Frogs, and Salamanders: A Spring Night at the Outdoor Lab”

JOIN THE 2026 CITY NATURE CHALLENGE

April 24-May 10, 2026 By Rosemary Jann This April 24–27, ARMN members will once again join other naturalists, as well as families, individuals, and/or groups across the greater Washington DC metropolitan area to participate in one of the largest citizen science events in the world: the City Nature Challenge. The event is a friendly competitionContinueContinue reading “JOIN THE 2026 CITY NATURE CHALLENGE”

It’s FINALLY Spring! A Great Time to Shop for and Install Native Plants

Text and photos by Kasha Helget After a rough winter, we’re experiencing warmer days and the return of birds, bees, and butterflies that depend on native plants to survive and feed their young. Native plants also provide beauty to our pots, yards, and landscapes. Where to find them? Actually, the timing is excellent because thereContinueContinue reading “It’s FINALLY Spring! A Great Time to Shop for and Install Native Plants”

The Evolving Role of Wildland Fire in Virginia

Arlington Forest Park, designated by Arlington County as a natural resource conservation area for its rare oak savanna ecosystem. Photo by Dan Brown. Nature parks in our area are managed to support native plant communities, often the oak/hickory forest type. But some parks don’t much resemble the original landscapes because a key factor is missing:ContinueContinue reading “The Evolving Role of Wildland Fire in Virginia”

The Hidden Helpers of Our Forests: Mycorrhizal Fungi and the Web of Life Beneath Our Feet

By Laura Gilmore Local forests depend on invisible partnerships beneath the soil. Photo of Long Branch Stream in Glencarlyn Park by Marianna Cardozo. When we walk through a forest in Northern Virginia, whether it’s the hardwoods of Potomac Overlook Regional Park or the woodlands of Glencarlyn Park in Arlington, it’s easy to focus on whatContinueContinue reading “The Hidden Helpers of Our Forests: Mycorrhizal Fungi and the Web of Life Beneath Our Feet”

Geology Walk in Holmes Run Gorge

Text and photos by Hutch Brown. On August 30, 2025, several ARMN members joined local residents for a geology walk in Holmes Run Gorge hosted by the Northern Virginia Mineral Club and Friends of Holmes Run. Holmes Run, part of Alexandria’s Cameron Run watershed, cuts a gorge through the Piedmont bedrock (the foundational rock underlyingContinueContinue reading “Geology Walk in Holmes Run Gorge”

2026 Martin Luther King, Jr., Weekend 

Nature Volunteering Events ARMN and other local environmental groups are hosting several events in honor of Martin Luther King, Jr. between Jan 16 and 19, 2026. Here is a list of opportunities to work with fellow community members to remove non-native invasive plants and clean up our area’s beautiful parks and spaces. Please check theContinueContinue reading “2026 Martin Luther King, Jr., Weekend “

Citizens Help Gauge the Health of Alexandria’s Streams

Volunteers sort through a stream sample for macroinvertebrates. Photo by Jennifer Fletcher, City of Alexandria Communications. By Devin Reese Urban streams get dirty—from trash, discharges, and street runoff. Yet, they have the potential to be the lifeblood of communities, offering a place for fishing, boating, picnicking, biking, birdwatching, and various activities that attract people toContinueContinue reading “Citizens Help Gauge the Health of Alexandria’s Streams”