Places We Protect

Nanjemoy Creek


Two people in yellow kayaks float together down Nanjemoy Creek. The smooth, flat water reflects the autumn colors of the trees that line the creek bank.

One of Maryland's most pristine watersheds.



Nanjemoy Creek Preserve was established to protect a large breeding colony of great blue herons that once nested here.  The herons have since moved on, but the preserve abounds with life. 

Local farmer and naturalist Calvert R. Posey, site manager for many years, kept a detailed field journal listing 48 tree species, 86 wildflowers (including rare Virginia wild ginger) and numerous creatures—snakes, skinks and salamanders, to name a few. Posey noted that his lists on this richly endowed place were by no means complete.

TNC's ultimate goal is to protect a forested ecosystem large enough to function as nature intended it, and also large enough to encompass most, if not all, common and rare species. Raccoons, bobcats, skunks and squirrels inhabit the woods; otters swim the creek; and the rare dwarf wedge mussel (found in only 20 sites worldwide) thrives in the sandy-mud bottom of stream banks. The deep forests here also attract many species of migratory songbirds.

Relatively few roads carve through these woods, though human activities like residential development and incompatible forestry threaten this emerald-green oasis. The Nature Conservancy has embraced the challenge: retain the character of one of the state’s most pristine watersheds, where just eight percent of the land is currently protected.

TNC has identified a project area of more than 48,000 acres offering the rare opportunity to save and restore this enormous block of contiguous forest. This remarkable situation exists, in part, because the landscape has not been fragmented as it has in other places—only about 150 private landowners own 25,106 acres (76 percent) of the unprotected land here.

Since establishing Nanjemoy Creek Preserve in 1978, TNC has worked to assemble the forest puzzle, helping conserve more than 3,510 acres to date (3,204 of which is TNC's preserve).

For more information about visiting Nanjemoy, contact Gabe Cahalan at 301-897-8570 or



Dogs are not allowed at this preserve.


Explore Nanjemoy through a self-guided audio tour.

Explore our work in Maryland/DC

Visiting Our Nature Preserves

Read our Preserve Guidelines to learn about permitted and prohibited uses, and ways of enjoying these spaces.

A NOTE ON HUNTING: Several TNC nature preserves in Maryland include hunting leases for deer management. Visit the Maryland Department of Natural Resources to find information on hunting season, licenses and access on public lands. When visiting a TNC nature preserve during hunting season, please wear blaze orange and try to avoid visiting in the early morning or evening hours when hunting is most active. For additional guidelines on how you can hike safely during the hunting season, visit the American Hiking Society.

Self Guided Audio Tour

Visit the Charles County Parks page to plan your visit and then download the audio tour map and driving directions. The letters marked on the map correspond to the audio files in the tour. 

Cell service may be unreliable at many of our preserves.  We recommend you download the recordings and maps before you visit.

Meet Your Guide

Deborah Barber is Director of Land Management for the Maryland/D.C. chapter. She enjoys exploring nature both on her own and with others, especially her children, who often spot interesting things that adults miss. She enjoys cooking, traveling, gardening, and learning about geology.

Donwload Audio Files (MP3)

A1: Introduction

A2: Boat launch point at Friendship Farm Park

A3: Trail head plants and Friendship Farm trails

B: Route 6 and Hancock Run Road

C: Nanjemoy Creek

D: Unnamed wetland

E: Purse State Park

F1: Chiles homesite

F2: Cal Posey Trail

G: Mallows Bay

Find More Places We Protect

The Nature Conservancy owns nearly 1,500 preserves covering more than 2.5 million acres across all 50 states. These lands protect wildlife and natural systems, serve as living laboratories for innovative science and connect people to the natural world.

See the Complete Map