SOMETHING HAPPENS to Americans when they get on a horse. They sit tall in the saddle, scan the horizon, ride into the sunset. True grit. Denny Glotfelty understands that. He's been taking people on horseback rides for 25 years, and he loves it.

"We try to give them scenery and the experience of being on a large animal that they can control and a chance to live out a little of the fantasy of the western movies and the pioneers," says Glotfelty, whose family operates the 200-acre Double G ranch at McHenry, near Deep Creek Lake. The Double G -- named for Gerald Glotfelty, Denny's father -- offers rides from half an hour to all day, and overnight and weekend camping trips plus hay rides and sunset rides.

Except for summer guides and instructors, all the hands at the working ranch are Glotfeltys.

The Glotfeltys raise, train and trade horses They also have cattle and small domestic animals such as ducks, geese and rabbits. Oats, corn and hay are raised for feed, and Denny Glotfelty does the haymaking himself.

The horse-riding part just sort of happened, Glotfelty says: "We had some horses, and neighbors would come by and ask to ride. And then more people began to come by, and 25 years ago, Dad decided to make it a business." Glotfelty was eight then.

Now 33, he runs the ranch, but his parents still live there and take care of the campground.

That sort of grew as the horseback riding did, he says, because people asked for it.

"We are a family business," Glotfelty says, "and we try to cater to families," although they get more women and children than men on rides, one reason most Double G trail guides are girls.

The ranch is open all year, but the most active season, of course, is July 1 through Labor Day.

DOUBLE G RANCH AND CAMPGROUND -- On Bumblebee and Mosser roads, 1/2 mile east of U.S. 219 on the north end of Deep Creek Lake. Horseback riding rates start at $5 for a half hour, $8 for an hour. Sunset rides with a fire and snacks are $10. The campground serves recreational vehicles and tenters; the tent site is in a grove of trees beside a small stream. Most sites have electricity and water. The basic fee is $7 per night, $1.50 electric and water, 50 cents for sewer hookup. Reservations are accepted with one night's deposit. Double G. Ranch, Box 25, McHenry MD 21541. 301/387-5481.