IF YOU WANT to learn about a river -- and you don't have a boat -- you've got to spend time on its banks. At Maryland's Susquehanna State Park you're free to roam the Susquehanna River's edge, and, if you feel like taking in a few museums, you can pick up a little of the river's history as well.

Located between Havre de Grace and Conowingo Dam, the Susquehanna State Park encompasses nearly 2,000 acres, some thickly wooded, and some, such as where the Steppingstone Museum and the park's campground are located, on high, dry, cleared land.

The Susquehanna is the biggest river feeding into the Chesapeake Bay, bringing in over 50 percent of the bay's fresh water. The river's watershed covers 27,500 square miles, roughly twice that of the Potomac. (In fact, if you want to get technical, the bay is really the drowned Susquehanna. When the polar icecaps melted and the sea level rose, the Atlantic flooded the lower reaches of the Susquehanna River, forming the Chesapeake Bay.)

Still, the Susquehanna appears less imposing than our Potomac. Here in the Susquehanna State Park, the mile-wide river is rocky and shallow, which makes for quiet boating, a lot of fishing and active waterbirds. The river bank is poison-ivy woodsy, but narrow foot trails lead to cleared spaces and flat rocks where you can set up chairs or stretch out by the water's edge.

The waterbirds are something to watch. Here at the park I saw my first great blue heron in Maryland. It was standing on a rock mid-river. And ducks, not the kind that beg for food either, land on and fly off the water continuously. Bald eagles, always an impressive bird, are very commonly spotted. I was told that they nest on an island up above Conowingo Dam and if you keep an eye out, you can see more than one at a time.

Up Deer Creek, which enters the Susquehanna in the park, the water runs quick, and tubing and canoeing are popular summer activities. In the Deer Creek picnic area are a small pond, ideal for fishing, and a large sunny field, perfect for playing Frisbee.

The focal point of the park is the waterfront Rock Run Historic Area. During the 1800s, this was a far busier spot than it is today. Overgrown pilings are all that's left of Rock Run Bridge, the first to cross the Susquehanna in Maryland. Built in 1818, this covered bridge was partially destroyed in 1854 by the vibrations of crossing cattle, and then swept away entirely by ice floes in 1856.

The ditch running alongside the river here is what remains of the once active Susquehanna and Tidewater Canal. Completed in 1839, the canal ran the 45-mile stretch from Wrightsville, Penn., to Havre de Grace, until floods closed it at the end of the century.

Several buildings in the park are restored and open to the public. The most impressive structure is the Rock Run Grist Mill with its 12-ton water wheel. Four stories high, it's both a museum of sorts and a working mill. Inside you'll find old milling machinery, a 1920s Post Office (on the second floor, at a height safe from floodwaters), sketches illustrating the ice industry along the river and old photos of the Rock Run and Conowingo covered bridges. (In 1928 the Conowingo Dam was built, putting both the bridge and the town of Conowingo under water.)

Midafternoon, between 2 and 4, the mill's water wheel is turned on, filling the mill with the rhythmic churning of the huge wheel and the sweet smell of cornmeal, ground on a buhrstone. The miller gives away samples, but the bag says "not distributed for human consumption" ( it's edible, but not inspected by the health department, I was told).

Up the hill from the mill is Rock Run House. If you enjoy going through old houses, this one, built in 1804, won't disappoint. The house is furnished, though all that remains from the original owners is an old desk with a nifty secret compartment. The kitchen was really up to date for the times, the tour guide told me. It included a "hot water heater" -- a space next to the huge brick fireplace that held a copper bucket filled with water from the nearby springhouse. Upstairs there's an interesting model of Rock Run in 1850 when the mill, the bridge and the canal were all functioning.

At the Toll House, the displays represent the river's past, present and future. You'll find old photos and a listing of toll charges for crossing Rock Run Bridge, information about today's park wildlife, and, finally, exhibits and brochures encouraging conservation measures, such as planting trees to reduce runoff in the river's watershed.

You'll have to get in your car to go to the park's privately operated Steppingstone Museum. In a beautiful setting atop a bluff, this farm museum houses the various shops and trades area residents once depended on. A volunteer blacksmith, woodworker, weaver and potter, all eager to chat about their work, were working in the shops when I visited.

A tour guide will take you through the restored stone farmhouse, built in 1798 and furnished as it would have been 100 years ago. Fanciers of lace should ask to be shown the lace collection upstairs where the bedroom and toy room are. (When the museum is short-staffed, the upstairs is sometimes not included, but express an interest and you might get to go up.)

Don't leave Steppingstone without walking around to the back of the house. From here, you can enjoy one last look at the Susquehanna before heading home.

Susan Glick last wrote for Weekend about introducing children to photography.