SMITHSBURG, Md. (AP) _ When fire destroyed their home and crop 13 years ago, fruit growers Samuel and Barbara Cool had to rebuild and rethink their business.

One idea that bore fruit was a commercial fishing pond, created from an old irrigation pond. Stocked with trout, bass, catfish and panfish, the spring-fed pond became the core of an enterprise that now includes a campground, farmstand and rustic craft store.

Those operations provide a third of the Cools' income, illustrating how farmers can profit from the public's growing appetite for outdoor experiences.

``What it's doing is trying to keep a family farm in the family,'' Mr. Cool said Monday as he showed a visitor around his scenic 100 acres on the mountainous Maryland-Pennsylvania border.

More and more farmers and other private landowners are learning to capitalize on their property's appeal to people hungry for contact with nature. Outdoor recreation has been rising in popularity since 1960, and private landowners can take advantage of the demand, according to U.S. Forest Service researcher H. Ken Cordell.

Bird-watching, hiking and camping are among the fastest-growing nature activities, he told landowners and rural development specialists at a recent regional conference in Hagerstown.

Private property abutting public land offers complementary opportunities, Cordell said. And he said there is a ``huge niche'' to be filled meeting the demand for recreation in areas with little public acreage.

Hunting and fishing show signs of waning but still offer good opportunities for private income, according to Cordell and Mike Hayden, president of the American Sportfishing Association in Alexandria, Va.

Hayden, a former Kansas governor, said he belongs to a private club in Kansas that welcomes the public for fee fishing, bird hunting and deer hunting on its lands. Bird-watchers also come to watch prairie chickens do their mating dance, he said.

Such enterprises pose risks, though.

``You're starting a business of sorts. To be successful at it, you've got to do your homework,'' said conference organizer Jonathan Kays of the University of Maryland Cooperative Extension.

Tracy and Barbara Cate, a Maplewood, N.J., couple who own a 180-acre farm near Marksboro, N.J., in Warren County, worried about damage and legal liability if they open their land to the public.

``I would love to control the deer population and the Canada geese, but to allow hunters in is to allow shooting,'' Mrs. Cate said. ``There are too many dangers involved when you invite the public.''

The Cools said they worried, too, before opening their fee fishing business in 1990. They said they feel sufficiently protected by their farm liability insurance, and they have had no problems with people going where they don't belong.

``I was sure everyone would be up at our back yard and on our porch but I blew that all out of proportion. They don't ever bother you,'' Mrs. Cool said.