At a Glance
Hours: 8 am. to sunset. All vehicles must exit the park before the gate closes at sunset.
• April-October, weekends and holidays: Maryland residents $3/person; out-of-state residents $5/person.
• April-October, weekdays: Maryland residents $3/vehicle; out-of-state residents $5/vehicle.
• November-March, daily: Maryland residents $3/vehicle; out-of-state residents $5/vehicle.
Tips: Try to visit on weekdays if you can. The park is tremendously popular with mountain bikers year-round and the parking lots may fill to capacity. There may also be large groups at the picnic pavilions and/or equestrian events on the weekends. ◾ Wear sturdy closed-toe hiking boots, preferably waterproof, as there are a couple of wet stream crossings and/or wet grass. You may want to bring a hiking staff; the trails are hilly and are slippery when wet. ◾ A compass or GPS would be helpful as many of the trails twist and wind and it is easy to lose your sense of direction. The park map at the link below is geolocator-enabled and can be loaded into an app on your smartphone to enable on-the-ground navigation of the major trails. ◾ If you fail to exit the park in time and get locked in, call Park Watch at 1-800-825-7275. ◾ Rosaryville State Park allows bow-hunting for deer in a designated area that covers much of the park. Be aware of hunting seasons and plan your visit accordingly. Be aware that hunters may hunt legally on park property outside of the regular posted park hours. ◾ Restrooms are available at the picnic pavilions and the trailhead parking lot for the Perimeter Trail, but are closed in winter. Portable restrooms may be available as replacements in winter.
Best Seasons: Fall through early summer.
Breeding Bird Atlas Blocks: Upper Marlboro SW, Upper Marlboro SE
Local MOS Chapter: Patuxent Bird Club
Rosaryville State Park
7805 West Marlton Avenue, Upper Marlboro, MD 20735
Rosaryville State Park is for birders who like to hike. Sure, the park has a visitor facilities core with paved roads so that there is birding from or near the car, but if you stick to the paved roads area, you’ll just be scraping the surface of the park’s many habitats. At 982 acres, the park is too large to cover on foot in one visit, so if you want to see the entire park, plan on repeat visits of several hours each. As of January 2020, funds have been approved for a 200-acre addition to the park, which will further expand the park’s hiker-birder opportunities. The need to cover the park on foot probably contributes to the fact that it is under-birded.
Rosaryville State Park is located just off US Route 301 south of the town of Upper Marlboro. It provides rare access to bird in the interior of southern Prince George’s County, as most of the public parks where birders congregate are on the county’s borders on the Patuxent or Potomac Rivers.
The park has three designated parking areas, all located on spurs that branch to the north side of the main entrance road. The first parking area on the right as you drive into the park is the designated parking for the trail system (marked as “Mountain Bike Trail Parking” on Google Maps), and includes restrooms and a memorial to the late Fred Eskew, former Program Open Space Director who worked to ensure the state’s acquisition and preservation of Rosaryville State Park. A spur road to the left provides access to a parking area designated for horse trailers. The park’s third parking area is located adjacent to the two covered picnic pavilions near the end of the main entrance road. There is no loop road – the entrance road comes to a turn-around just past the picnic pavilion parking and then you head out the way you came in.
The historic Mount Airy Mansion, dating to the 1700s, is located in the southwest part of the park. The elegant mansion is not open for public tours, but can be rented for weddings and other formal events. The mansion’s old greenhouses are used by the non-profit Chesapeake Natives organization, whose volunteers grow native plants for sale to the public. Thanks to Chesapeake Natives, the grounds surrounding the mansion have been planted with pollinator gardens, which are also attractive to seed- and insect-eating birds. The forest around the mansion contains many magnificent old specimen trees. A small freshwater pond, called Dower House Pond, and an adjoining wetland, is next to the mansion’s driveway off Rosaryville Road. At any time, it is possible to hike to the mansion area using the foot-trail system of the park, but there is no public access to drive to the mansion from within the park. Instead, the mansion has a separate driveway from Rosaryville Road, but this is only open to the public for native plant sales. Hence, if you want to visit the mansion area for the good birding around it, you will have to do so on foot. See “A Word about Watersheds” below for some interesting facts about Dower House Pond and its vicinity.
An extensive trail system permeates the entire park. The Perimeter Trail that encircles the park is about 9.7 miles in length, but in many spots there are short-cuts and long-cuts that can result in shorter or longer distances. Note that the narrow and twisty Perimeter Trail experiences heavy use by mountain bikers ─ be prepared to jump aside when bikers are passing you. You may want to opt for other trails in order to avoid the largest contingents of bikers. There is an extensive network of shorter trails criss-crossing the park and these tend to be less popular with the bikers; some, but not all of these trails, are shown on the official park map at the link at left. In bygone days, when the park was a private estate, the trail system supported extensive equestrian use as well as farming needs. In short, the elaborate trail system allows you to plan a hike of any length and go to any part of the park that you choose. Be aware that the hilly terrain can make most hikes seem longer than they are.
The majority of the park’s acreage consists of deciduous forest with both dry uplands and moist stream valleys and floodplains. There are some small conifer woodlots, particularly near the historic Mount Airy mansion in the southwest corner of the park. Charles Branch, a tributary of the Western Branch of the Patuxent River, flows through the northeast quadrant of the park, and smaller tributaries are found throughout the wooded areas, with a major stream flowing along most of the park’s northern border and another on the eastern edge parallel to US Route 301. An excellent view of the Charles Branch Stream Valley can be obtained from the “Scarlet Tanager Overlook,” located on the Perimeter Trail just northeast of the parking area (see trail map at link at left). The wooded areas are great for tanagers, flycatchers, vireos, thrushes, and warblers during spring migration and in breeding season, and in winter hold kinglets, nuthatches, and bluebirds. Adding to the charm of the park, the woods and wood edges are peppered with old tobacco barns, silos, sheds, and other remnants of its days as an active farm.
There is a wide power line cut that traverses the rolling hills of the park, bisecting it from northwest to southeast. A mowed path runs under the power lines and intersects with major foot-trails that run east-west through the woodlands. Several stream valleys cross the power line cut, and these low areas contain pockets of shrubby vegetation that attracts sparrows and finches. The power lines themselves are a favorite hangout for raptors, bluebirds, kingbirds, and other perch-hunters, and the edges of the power line cut attract phoebes, pewees, Cedar Waxwings, robins, wrens, and chats. For best access to the power line cut, park near the picnic pavilions (see trail map at link at left) and continue on foot up the slope on the gravel service road that extends beyond the end of the paved park road.
The main parking lot for the trail system is located in a wooded glen; the edges of this glen provide good birding, and there is a planted raingarden/stormwater retention pond near the restrooms that is attractive to Common Yellowthroat, wrens, and flycatchers. Shrubby areas along the road to the parking area also provide good birding. There are additional, recently completed vegetated stormwater retention areas adjacent to the other parking areas, and all of these should be checked by the assiduous birder. Another good spot is a native grass restoration area near the picnic pavilion parking area; this area is easily found on the north side of the main entrance road near its end, and is marked with interpretive panels.
The park has a trail called the “Grasslands Bird Trail,” and a prominent interpretive panel just beyond the entrance booth pictures such birds as Northern Bobwhite, Eastern Meadowlark, Bobolink, Grasshopper and Vesper Sparrow, Horned Lark and Dickcissel. Sadly, none of these birds are found here any longer, because of changes in the management of the majority of the grass fields that surround the parking areas. Formerly thriving with warm-season native grasses, these fields are now planted with fescues similar to those used on sports fields, kept short by mowing, and not supportive of nesting birds.
A Word about Watersheds:
Most of Rosaryville State Park – about 84% – lies within the Western Branch Patuxent Watershed. This part of the park is drained by Charles Branch, which flows east through the northeast corner of the park to enter the Western Branch, and from there the water flows into the mainstem of the Patuxent River, located east of Rosaryville State Park. Charles Branch has many tributaries within the park, all of whose water eventually ends up in the Patuxent River. But, the area at the southwest corner of the park is different: here, along the driveway leading to the Mount Airy Mansion, there is a basin that drains into Dower House Pond, which forms the headwaters of Dower House Pond Branch, a tributary of Piscataway Creek, which flows west into the Potomac River. Thus the park straddles two of Maryland’s major watersheds. There is a ridge line running almost due north-south located between the Mount Airy Mansion driveway and the power line cut; this ridge line forms the dividing line between the Charles Branch – Western Branch – Patuxent River drainage and the Dower House Pond – Piscataway Creek – Potomac River drainage. Below the Mount Airy Mansion, this ridge turns west and forms an arc that crosses the driveway. See our watershed map of Rosaryville State Park to visualize this, and be aware of the change in topography the next time you hike and bird around the Mount Airy Mansion and Dower House Pond.
The eBird hotspot for Rosaryville State Park lists 101 species as of Spring 2021, but there are only 40 checklists entered, all since 2014. The checklists fail to capture the earlier glory days of the park, when it was teeming with grassland birds. Although bobwhite, meadowlarks, bobolinks, and dickcissels no longer breed here, there is still ample reason to visit the park and help build up the list of reported birds in its woodlands and shrubby areas.
Canada Geese occur as flyovers as well as at the small freshwater pond by the driveway into the Mount Airy mansion. Wood Ducks were confirmed breeders in the past, but it is unclear if they are still here. There may also be Mallards at the pond.
Wild Turkeys inhabit the upland forests and may be found in clearings and fields in early morning and late afternoon. Mourning Doves are abundant. Chimney Swifts are almost always overhead from April through October. Be alert for American Woodcock in wet woods in winter.
With wide open skies near the picnic pavilion or the power line cut, watch for raptors overhead. Black and Turkey Vultures are abundant; Osprey sometimes drop in or flyover; and Bald Eagles can also be found. Red-shouldered, Red-tailed and Cooper’s Hawks are probable breeders. American Kestrels formerly bred here and it may still be possible to find one or two – the best place would be the power line cut. All three owls – Great Horned, Barred, and Eastern Screech – are expected. Check around the old abandoned barns and silos and also in the pine woodlots near the mansion.
Belted Kingfishers can be found near the pond and also along the Charles Branch or its larger tributaries. Woodpeckers include Yellow-bellied Sapsucker (winter), Red-bellied, Downy, Hairy, Pileated, and Northern Flicker. All the usual flycatchers can be found: Eastern Wood-Pewee, Eastern Phoebe, Great Crested Flycatcher, and Eastern Kingbird.
Both Red-eyed and White-eyed Vireos breed here, and Blue-headed can be found during migration. Blue Jays and American Crows are numerous, as are Carolina Chickadees and Tufted Titmice. The wide open fields attract Tree and Barn Swallows. Watch for Purple Martins overhead during migration.
In the winter, expect Ruby-crowned and perhaps Golden-Crowned Kinglets, as well as Brown Creepers. White-breasted Nuthatches are an abundant breeding resident. Blue-gray Gnatcatchers are easy to find in forests and edges from April through fall. Carolina Wrens will surely greet you when you arrive and no matter where in the park you go. There may also be House Wrens, especially near old barns, and Winter Wrens near streams in winter. All three mimids – Gray Catbird, Brown Thrasher, and Northern Mockingbird – have breeding populations.
For thrushes, we have year-round Eastern Bluebirds (numerous) and American Robins; a robust breeding population of Wood Thrushes; wintering Hermit Thrushes in good numbers; and an occasional migrant such as Veery. Cedar Waxwings can often be found feeding in berry-laden trees.
A few House Sparrows and House Finches may be about, but they are not particularly numerous. There may be Purple Finches in winter; check tangled areas near old barns and on the edges of the power line cut. American Goldfinches occur throughout the park.
Breeding sparrows include Chipping, Field, Song, and Eastern Towhee. In winter, look for Fox, Swamp, White-throated, and Savannah Sparrows and Dark-eyed Juncos. The power line cut, the shrubby fields, the restored native grass plot, and the gardens near the mansion are good places to look. Also be on the lookout in these areas for Yellow-breasted Chat.
Orchard Orioles breed here; check along the Agricultural Heritage Trail as well as the power line cut. European Starlings are present but, surprisingly, not in large numbers. Red-winged Blackbirds, Brown-headed Cowbirds, and Common Grackles are all numerous, especially near the private farms that border the park’s southeastern edge. In late winter, you may be lucky to find Rusty Blackbirds among them. Also check for Rusties near Dower House Pond.
As of Spring 2021, there is a modest list of 15 species of warblers, but no doubt more will be found with additional visits. Breeding warblers include Overbird, Louisiana Waterthrush, Common Yellowthroat, Hooded, and Norhern Parula, and possibly Black-and-white, American Redstart, Yellow, Pine, and Yellow-throated. Yellow-rumped Warblers are common in winter.
Scarlet Tanagers are easy to find, and Summer Tanagers have recently been added to the park’s list. Northern Cardinals, Blue Grosbeaks, and Indigo Buntings are all easily found and have breeding populations.
Pets on leash are permitted; be prepared to pick up after your pet.
Some birding is possible from or near the car using the paved roads and parking areas. None of the foot-trails are wheelchair-accessible. The restrooms and portable restrooms are wheelchair-accessible.
The core of Rosaryville State Park, containing the parking areas, picnic pavilions, restrooms, and trailhead, is named the Fred Eskew Memorial and Recreation Area, in honor of the late Fred Eskew, who dedicated his career to recreation and land preservation in Maryland, serving with the Prince George’s County Department of Recreation, the Charles County Department of Parks and Recreation, and the Maryland Department of Forests and Parks. Mr. Eskew was ultimately appointed as the Director of Program Open Space (POS), Assistant Secretary of the Maryland Department of Natural Resources, and the Governor’s State Outdoor Recreation Liaison Officer. In particular, Mr Eskew worked to save the land that is now Rosaryville State Park from development.
The Mount Airy Mansion has an interesting history dating back to the 1700s and earlier. ◾ Chesapeake Natives is a non-profit organization that uses the greenhouses at the Mount Airy mansion to grow plants native to the Chesapeake Bay Watershed for sale to the public. Chesapeake Natives is open to the public on special plant sale days and by appointment. In addition to its public sales, the Chesapeake Natives volunteers have planted and maintain pollinator gardens near the mansion, and engage in habitat restoration projects. Educational programs are offered through schools and community groups.
The local chapter of the Maryland Ornithological Society is the Patuxent Bird Club, which offers field trips and meetings with informative programs, all free and open to the public.
Three designated paved lots as shown on the trail map at the link at left. The middle lot is designated for horse trailers but it is acceptable to park a car there if there is sufficient space.
Rosaryville State Park is located south of the Town of Upper Marlboro in Prince George’s County and the entrance is located off of US Route 301 on the southbound side.
From the Baltimore area: From the Baltimore Beltway/I-695, take Exit 4 for I-97 southbound. In 9.8 miles, take Exit 7 for MD Route 3 southbound toward Bowie. In 9.5 miles, Route 3 will cross under US Route 50, and at that point, US Route 301 southbound will merge with the road you are on, known as Robert Crain Highway. Continue south on Route 301 for another 14 miles, passing the outskirts of the town of Upper Marlboro. You will come to an intersection with MD Route 382/Croom Road on the left and a shopping center on the right. The next road to the right, just after the shopping center, is Osborne Road, and the next right after that, which comes up very fast in just 800 feet, will be the entrance to Rosaryville State Park. Turn right here on West Marlton Avenue and after passing a couple of houses on the right, in 0.2 miles turn right at the sign onto the main park road. The entrance fee station will be straight ahead in a quarter-mile. Ignore the old parking area that is chained off on the right just before the pay station; it is no longer in use.
From the Eastern Shore via the Chesapeake Bay Bridge: Use US Route 50/US Route 301 to cross the Chesapeake Bay and continue on Route 50/301 past Annapolis. Take Exit 13 and follow signs for US Route 301/Robert Crain Highway southbound. Continue south on Route 301 for another 14 miles, passing the outskirts of the town of Upper Marlboro. You will come to an intersection with MD Route 382/Croom Road on the left and a shopping center on the right. The next road to the right, just after the shopping center, is Osborne Road, and the next right after that, which comes up very fast in just 800 feet, will be the entrance to Rosaryville State Park. Turn right here on West Marlton Avenue and after passing a couple of houses on the right, in 0.2 miles turn right at the sign onto the main park road. The entrance fee station will be straight ahead in a quarter-mile. Ignore the old parking area that is chained off on the right just before the pay station; it is no longer in use.
From the Annapolis area: Follow US Route 50/301 westbound and use directions as above for people coming from the Eastern Shore.
From Washington, DC and Western MD: If coming from Western Maryland, use I-70 eastbound and then I-270 southbound to reach the DC Beltway/I-495. Take the inner loop of the Beltway to head to the east side of DC. Take Exit 11 for MD Route 4 south and east toward Upper Marlboro. In 3.3 miles, take the unnumbered exit for MD Route 223/Woodyard Road southbound and then in just 700 feet at the first street, turn left to go east on Marlboro Pike, which will shortly make a sharp bend to the right and after passing William Beanes Road on the left, the name of the road will change to South Osbourne Road. Continue south on Osbourne Road for 2.8 miles. At the intersection with US Route 301, turn right to go south. The next road to the right, which comes up very fast in just 800 feet, will be the entrance to Rosaryville State Park. Turn right here on West Marlton Avenue and after passing a couple of houses on the right, in 0.2 miles turn right at the sign onto the main park road. The entrance fee station will be straight ahead in a quarter-mile. Ignore the old parking area that is chained off on the right just before the pay station; it is no longer in use.
From points east in Calvert County or southern Anne Arundel County: Use MD Route 4 north and west bound to reach Upper Marlboro. At Upper Marlboro, take the unnumbered exit for US Route 301 southbound. Follow Route 301 southbound for 4.5 miles. You will come to an intersection with MD Route 382/Croom Road on the left and a shopping center on the right. The next road to the right, just after the shopping center, is Osborne Road, and the next right after that, which comes up very fast in just 800 feet, will be the entrance to Rosaryville State Park. Turn right here on West Marlton Avenue and after passing a couple of houses on the right, in 0.2 miles turn right at the sign onto the main park road. The entrance fee station will be straight ahead in a quarter-mile. Ignore the old parking area that is chained off on the right just before the pay station; it is no longer in use.
From points south such as Waldorf in Charles County: Use US Route 301 northbound and head toward Upper Marlboro. Start watching mileage from the intersection of US Route 301 with MD Route 5; the entrance to Rosaryville State Park will be 7.4 miles north of this intersection, on the southbound (opposite) side of Route 301. There is a crossover that will allow you to make a left turn, onto West Marlton Avenue, to reach the park. The crossover just under a half-mile mile north of the traffic light at the intersection with Heathermore Boulevard at a development called Marlton. Turn right here on West Marlton Avenue and after passing a couple of houses on the right, in 0.2 miles turn right at the sign onto the main park road. The entrance fee station will be straight ahead in a quarter-mile. Ignore the old parking area that is chained off on the right just before the pay station; it is no longer in use.
Prince George’s County: Beltsville Agricultural Research Center (restricted access) ◾ Bladensburg Waterfront Park, Colmar Manor Community Park & Anacostia River Trail ◾ Fort Foote Park ◾ Fort Washington (National) Park ◾ Fran Uhler Natural Area ◾ Governor Bridge Natural Area ◾ Greenbelt (National) Park ◾ Greenbelt Lake Municipal Park (Buddy Attick Lake Park) ◾ Lake Artemesia Natural Area ◾ Merkle Natural Resources Management Area ◾ Milltown Landing Natural Resources Management Area ◾ Oxon Cove Park & Oxon Hill Farm ◾ Patuxent Research Refuge – South Tract (National Wildlife Visitor Center) ◾ Patuxent River Park – Jug Bay Natural Area ◾Patuxent River Park – Mount Calvert Historical & Archaeological Park ◾ Piscataway MOS Sanctuary ◾ Piscataway (National) Park: National Colonial Farm, Boardwalk, Wharf Road/Farmington Landing & Marshall Hall ◾ Rocky Gorge Reservoir – Supplee Lane Recreation Area & Duckett Dam ◾ Schoolhouse Pond
Anne Arundel County: Jug Bay Wetlands Sanctuary
Bottomland DeciduousConifersHedgerowsUpland Deciduous Lawn, Ballfields, Golf Course Hay Meadows, Pasture, Grass FieldOld Fields, Shrubby Meadows Forested SwampFreshwater Marsh or FloodplainFreshwater Pond, Lake, or ReservoirRivers & Streams
Features and Amenities:BeginnersBicycle Trails (Bikes may be prohibited on some trails)FishingHabitat Restoration ProjectHiking/Walking TrailsHistorical FeaturesHorseback RidingHuntingNative Plant Garden or Meadow/Pollinator PlantsParkingPets AllowedPicnic AreaPlaygroundRestroomsWheelchair Accessible FeaturesYoung People / Families