“Celebrating Our Past, Creating Our Future.”

 Patapsco Valley State Park's Grist Mill Trail Offers a Stroll through Hisory

Patapsco Valley State Park, which dates back to 1907 and is one of Maryland's oldest state parks, lies in a steep river valley and extends along 32 miles of the Patapsco River. The river valley and its natural resources have long been enjoyed by the Native Americans, explorers and settlers as well as present-day citizens, and the park is nationally recognized today for its trail opportunities and scenery.

This stone bridge, built in 1869, replaced the original 1930's bridge, which was destroyed by floodingPatapsco Valley State Park encompasses 16,000 acres and five developed recreational areas. It is home to 170 miles of rugged, natural-surface trails that climb the hillsides along the river, popular among mountain bikers, equestrians and distance hikers. But one need not be a triathlete to enjoy the park's amenities. For those looking for a less strenuous workout, there is the Grist Mill Trail, a more moderate route and popular destination for parents with children in strollers, families on biking trips and people with disabilities. The Grist Mill Trail parallels the river for a mile and a half and provides a close-up view of its scenic beauty, while leading past numerous sites of historic interest.

In the fall of 2003, a new multi-use section of the trail opened near Ellicott City to enhance ADA- (Americans with Disabilities Act) accessible recreational opportunities. The original section of the Grist Mill Trail connects the famed swinging bridge in the Avalon Area of the park to Lost Lake, a special fishing area for children under age 16, senior citizens and visitors with disabilities, and once a reservoir for the Avalon Iron and Nail Works and the Baltimore County Water Company. The 1.2-mile extension leads from the swinging bridge to the river's edge near Ilchester. The trail temporarily terminates at an old railroad bridge abutment, but plans are in place to build a bridge over the river to connect to local roads. The new segment brings the total amount of paved trails in the park to slightly more than 2 1/2 miles and extends the Grist Mill Trail to a distance of five miles.

Trail users stroll past several historic sites worth noting. The Patapsco Valley's rich resources attracted entrepreneurs who harnessed the river's waterpower for 18th and 19th century industries, and because of its proximity to Baltimore, it served as a gateway between western Maryland and the Chesapeake Bay. As a result, the valley was developed as a transportation route and serves as a crossroads for the National Road, regional turnpikes and the Baltimore and Ohio (B&O) Railroad. Remnants of these early industries and the railroad can still be seen along the trail.

An observant cyclist or hiker may serendipitously find the ruins of the Orange Grove Flour Mill, which opened in 1856, and the Bloede Dam, an engineering feat of the early 20th century. It was the first hydroelectric dam in the U.S. where the turbines are located inside its hollow core, maximizing efficiency in power generation.

The original path of the B&O Railroad between Baltimore City and Ellicott City (1830) is also here; these were the first 13 miles of railroad track laid in the country. Horses drew the original rail cars while the steam engine was being perfected. Relics from the B&O Railroad include portions of the Patterson Viaduct and granite stringers that were used to hold the earliest iron rails that formed the railroad.

Historic photo of Patapsco swinging bridgeThe park's legendary swinging bridge was once used by flour mill workers walking from their homes in the town of Orange Grove on the west side of the river in Howard County to the saw mills on the east side of the river in Baltimore County. Visitors can also see railroad tanker ruins and the lasting effects of erosion along the riverbank dating back to Tropical Storm Agnes in 1972.

A self-guiding heritage tour map is currently available in park offices [$1.00] that explains historic sites on the original portion of the trail.

To get to the Avalon Area of Patapsco Valley State Park from the Baltimore Beltway (I-695), take Route 1 (exit 12A) south toward Arbutus. Follow Route 1 for approximately 3 miles to South Street. Turn right. The park entrance is on the left. To get to the park from I-95, take I-195 east toward BWI Airport. Take Route 1 (exit 3) south toward Elkridge. Turn right onto South Street. The park entrance is on the left. Patapsco Valley State Park includes land in Baltimore, Anne Arundel, Howard, and Carroll Counties. For more information on the trail, call or visit the Avalon Visitor Center, 410-737-0451.


  • Interpretive signs for all of these sites are slated to be in place for the Summer 2006 season.
  • A new bridge connecting the Grist Mill Trail with Howard County is underway.

Note: Anne Kernan was a Park Naturalist at Patapsco Valley State Park when she wrote this article for the Summer 2004 issue of the The Maryland Natural Resource magazine. Our thanks to Robb Bailey for his 2006 up-dates to this article.

Two modern day photos courtesy of Anne Kernan.