The wetlands in Cheltenham Wetlands Park have gone dry, causing the cancellation of most programs for the public at the 200-acre reservation in southern Prince George's County.

"We had dip-net hikes, a swamp stomp and wetland wading, where we go in the water, but there isn't any water," said Lisa Garrett, a park naturalist at the Clearwater Nature Center in Clinton, which manages the Cheltenham tract.

Programs at Cheltenham, off Route 301, are scheduled months in advance and require advance registration. Callers are being told of their cancellation due to the drought.

At Clearwater, the effects of the dry spell have spilled over into other programs. "We wanted to go whitewater rafting with a group of 20 kids the other week and had to change from the Shenandoah to the Potomac" because of water levels.

Earlier this year, February's unseasonably mild weather also caused a change in plans. "We had hot cocoa campfires, and it was 75, so we had lemonade, and we had a campfire," Garrett recalled.

But the scorching heat has done away with summer campfires entirely, for the second straight year, Garrett said. "Because of drought, we had to be concerned with fires," she said.

However, it is in Cheltenham, a former Navy communications site now owned by the county and accessible only by appointment, where the heat wave has had its most searing effect. "Today, deer are running through a field I remember a couple of years ago being a big swamp," Garrett said.

"If you went on the boardwalk [at Cheltenham] and took a picture, you'd see big grassy fields. It's obvious, you wouldn't build a boardwalk through a field," she said.

There is still a trickle of water in the creek at Cheltenham, but not much. Beavers that used to swim down the middle now walk it. "They're adapting," Garrett said.

And so are the park people.

"We can still do hikes, but we're not seeing wetland creatures and plants you'd normally see," Garrett said. "Instead of going on a hike and looking for creatures with a net, we walk on the boardwalk and look for butterflies, deer and squirrels."

Altogether, a total of eight wetlands programs have been canceled at Cheltenham, where only rainwater keeps them wet. About 200 people a year participate, many in family groups.

As bad as things are now, Garrett said, last summer was worse. "We had creek walks here at [Clearwater] park, and at Cheltenham, we had to cancel because there was no water in either creek."

Piscataway Creek, which runs through Clearwater, is even drier than the creek in Cheltenham this year. "At Clearwater, we changed programs, but we still have them. We went on a bat hike instead of a beaver hike. But people go to Cheltenham specifically to see the wetlands. . . .

"It has been kind of disappointing from a wetland watchers viewpoint. But hopefully we'll have a wet fall, and it will recover and we'll be able to schedule trips in."