John Reiss and Richard Brown are two of six captains who conduct free tours on the Anacostia River using boats operated by the Maryland-National Capital Park and Planning Commission. (Hamil R. Harris/The Washington Post)

John Reiss reversed the engines of the big pontoon boat and backed away from Bladensburg Waterfront Park on a recent lazy Sunday afternoon, ready to sail down the Anacostia River with about 20 passengers.

The high tide and cool breeze offered a postcard-perfect opportunity for people to get acquainted with a river that, for the past 25 years, has been one of the area’s most endangered resources because of decades of neglect and pollution.

But now, the brown waters of the Anacostia conceal the mud bars, and birds are flying and diving into the river to catch fish. In the years to come, people will be able to ride a bike along the banks of the river from College Park to Southwest Washington.

“Twenty-five years ago . . . cars and refrigerators were in the river,” said Lee Cain, director of recreation for the Anacostia Watershed Society. “Now we are focused on things like plastic bags, Styrofoam and bottles, and even a lot of that is out of the river because of the bag fee and pending legislation.”

Cain also said that, because of efforts to clean up the river, “there is 50 percent less cancer in the fish than . . . 10 years ago, and we are on track to have 85 percent of the sewage out of the river.”

Reiss, 75, a retired carwash operator, said he enjoys taking people on boat tours.

“I just want people to get whatever it is that they enjoy,” he said. “It is something entirely different than what they do in everyday life.”

Reiss is one of several captains who drive boats up and down the Anacostia six days a week for free tours. The watercraft are operated by the Maryland-National Capital Park and Planning Commission.

“This is a dream job,” said John Milligan, a Hyattsville resident and boat captain. “It is like working at the beach for me. I worked for the D.C. courts for 32 years. I would have done this for free.”

Another captain, Richard Brown, is well versed on the history along the banks of the Anacostia, including the Battle of Bladensburg during the War of 1812 and the spot where Maryland pioneer Stephen Decatur died in a duel.

Part of Brown’s mission is to clear up misinformation. He said the Peace Cross, a 40-foot memorial at Bladensburg Waterfront Park, was erected in honor of those who died in World War I, not the War of 1812.

In addition to increased river activities, the Anacostia Water Trail is under construction. The bike trail will connect College Park in Maryland to Nationals Park in the District. Cain said the trail will allow more people to enjoy the river.

“When people can get out and they can see the beauty of the Anacostia River, everybody becomes invested in it,” he said.

For Susan Punnett, a resident of Capitol Hill, the Anacostia River is special.

“It is D.C.’s river,” she said. “The Potomac is the national river, but the Anacostia is our river, and it is beautiful.”