Merkle Wildlife Sanctuary

11704 Fenno Road

Merkle Wildlife Sanctuary is the only wildlife sanctuary operated by the Maryland Department of Natural Resources. It is the wintering ground for several thousand Canada geese, the largest concentration on the western shore of the Chesapeake Bay.

As the wintering ground for the largest concentration of Canada geese on the Chesapeake Bay's western shore, Merkle Wildlife Sanctuary is one of Maryland's most unique Natural Resource Management areas.


There are four hiking trails at Merkle Wildlife that explore the upland forests and marshes of the Patuxent River. Our trails are open to hikers only. Bikers and equestrians may visit nearby Rosaryville State Park or Cedarville State Forest. All trail distances are round-trip, measured from the Visitor Center (except Lookout Creek Trail).

Paw Paw Trail
This is a flat, family friendly trail that weaves past streams and ponds and through forests and fields. Look out for paw paw trees along the trail that grow green,oval shaped fruits. Paw paws are the largest fruit native to maryland and were a favorite dessert of President George Washington. This trail is 1.2 miles long and is rated easy. The trail is blazed yellow.

Poplar Springs Trail
This is a relatively flat trail that connects the forested areas on either side of the main entrance road of Merkle. Named for the native poplar tree, this trail passes Merkle Wildlife’s champion yellow poplar which measures 116 feet tall and nearly 17 feet in circumference. Poplar Springs is 3.0 miles long and is rated easy/moderate. The trail is blazed red.

Mounds Trail
This is a hilly trail that follows along the top of a ravine and offers views of Lookout Creek. It’s most unique features are the large, man made mounds of dirt known as “ha-has” that give the trail its name. While their exact purpose is unknown, they are believed to be either early boundary markers or defenses built by soldiers during the War of 1812. This trail is 2.3 miles long and rated moderate. Mounds trail is blazed blue.

Lookout Creek Trail
This flat, figure-eight shaped trail winds through forests and wetlands. Named for Lookout Creek which feeds into the Patuxent River, hikers will get a beautiful view of the water and encounter various species of waterfowl and wetland vegetation. This trail is .72 miles and can only be accessed from the Critical Area Driving Tour (CADT). Lookout Creek Trail is blazed white.


Merkle has five fishing ponds open to the public.They are stocked with largemouth bass, bluegill, and various other species. Along with fishing, visitors can also enjoy wildlife observation and photography as these ponds provide prime habitat for a variety of wildlife.

Merkle ponds open April 1st of every year and close October 1st of every year. Please obey park hours.

If you plan to fish, please sign-in at our sign-in box located outside of the visitors center. Please obey the special fishing guidelines specified on the sign-in sheet and make sure you have your fishing licenses. All vehicles should be parked at the visitor center. Special parking arrangements can be made for those with disabilities who have an Access Maryland pass.

Fishing is regulated to help us manage the fish populations within the pond. Be aware that only two fishing lines may be in a pond at a time. If you have two lines, you are the only one allowed to fish. If someone else has a line in, you may only fish with one fishing line.


Upper Marlboro is home to one of the most diverse bird populations in Maryland.

Don’t forget to bring your binoculars!

A large bird viewing area with field I.D. books within the visitors center offers many hours of enjoyment