My communing with Mother Nature is consciously confined to my vegetable garden. But when a friend announced that her family had spent the night in a tree house, I didn't think. I just blurted out, "Hey kids, wouldn't that be fun?" Daddy doesn't do woods, so I found that I'd volunteered for a solo assignment.

Heading north on I-270 under a wide blue sky, I was grateful for my impulsive nature. The 45-minute drive through gently rolling farmland toward Frederick, with a short left jog on Route 17, was easy. Before the kids could begin their "When are we going to get there?" chant, we were there. Maple Tree Campgrounds is just around the bend from the Gathland State Park entrance, just up the mountain from Burkittsville.

A country cottage at the front of the drive is the check-in spot; you'll know you're there when you sight the large white tepee at the end of the drive.

An acre or so of clearing stretches back to the road, accommodating the communal bathhouse connected to the owner's comfortable digs. Twenty-six acres of woods stretch up the mountainside secluding four tree houses built around the substantial trunks of trees, a fully insulated log cabin situated beside a small creek, nine tent sites with all amenities and three primitive sites for purist campers.

Our place boasted two double beds built against the wall, a wood stove, table with benches and a filled wood box. Built on stilts seven feet off the ground, it qualified as a tree house for my four-year-old and six-year-old.

The kids busied themselves gathering kindling while I unpacked the hot dogs, chips, punch and cupcakes, a dubiously nutritious meal the children had planned. Starting the fire took some time for this band of tenderfoots, but we had left time behind at the entrance and there was no schedule to keep. As the kids roasted marshmallows over the dying fire, they asked, "Why do they have so many more stars in the country, Mommy?"

When the frosty nip turned to bite, we retired to our tree house, stoked the wood stove and played poker by the light of a kerosene lamp. One last flashlight-guided trip to the bath house and we rolled into our sleeping bags. During the night, cold winds sniffed around our cabin -- the only insulated tree house -- but everyone slept on, warmed by the cozy glow of the woodstove, and rose with Mother Nature at six.

After another woodsy meal of blueberry muffins and bagels and cream cheese, we hiked up the mountain to inspect the other tree houses, log cabin and tent sites. Since no one was occupying the tepee, my Indians did while I straightened up the tree.

Then, armed with a rundown on the things to see in the area -- zoo, antique shops, fishing holes, hiking trails, canoeing spots and crystal caverns -- we chose the caverns.

A 20-minute trip through Boonsboro led us to the first sign advertising the Crystal Grotto Caverns. The caverns -- open year round, admission $2 -- were unearthed by a blasting fluke during a state roads project in the '30s. The guides are local folks well schooled in speleology.

Winding through underground paths inspecting lighted rock formations fascinated the kids, but they were slightly unnerved at what the guide referred to as "total darkness" -- meaning she turned out all the lights. "Can you see the person standing next to you?" she cheerfully asked, knowing that her hand was on the light switch. "It better be my mother," Katy answered with a quaver.

Our next stop was Middletown for an ice-cream cone at the local confectionery. While the owner chit-chatted with the kids about camping and caves, she actually poured out a pot of coffee, explaining, "That's been on for a while, honey. Sit a minute, while I make a fresh pot." Honest.

As we checked out -- paying $25 for one night -- we stopped to chat with Maple Tree owner Phyllis Soroko. The kind of grandmother little boys dream of, Soroko made camping a large part of her life growing up in England and working in the Washington bureaucracy. She bought the land in 1976 after she retired and "was looking for something to do in my dotage." Soroko initially intended to set up a regular campground, but the inventive nature of Maple Tree is the result of what she calls the natural evolution of revulsion.

"I thought about tearing up all this lovely ground and turning it into 'dumpsites' and -- " she shrugs and pours another cup of tea.

Soroko has a real love for what she calls an "honest camper" and seems to get a kick out of young campers' instant love affair with her place.

On the drive back home, my son began plans for our next camping trip. "When we come back, let's stay for four days and nights in the house built around the tree." "No, let's stay in the tepee," chimed in my daughter, "and let's bring Daddy." TREEHOUSE TRIPPING For information and reservations, contact Dola Burkentine, Camp Manager, Maple Tree Camp Ltd., Townsend Road, Gapland, Maryland, 21736, 301/432-5585.