WITHIN TWO HOURS of D.C., you can drive a little- known route straight to the heart of one of Maryland's largest forests. The gravel road that winds for 25 miles through Green Ridge State Forest in the Appalachian mountains of Allegany County cuts through dense stands of brilliantly colored maple, oak, poplar and black gum, twisting past breathtaking overlooks and through woods filled with white-tail deer, grouse and wild turkeys.

And unlike driving such popular fall routes as Skyline Drive, which draws extremely heavy traffic, chances are you'll hardly see another car for most of your tour in Green Ridge, unless this article changes all that. Despite its 40,000 acres (making it Maryland's second largest state forest) and its proximity to D.C., Green Ridge is one of Maryland's best-kept secrets.

"This is nature at its finest," says forest manager John Mash. "You can go out here and take a walk and spend the whole day and not see another person."

Even if you're not up to a hike, the drive still lets you feel the closeness of the forest as the rough gravel road, gullied by rain, leads you deep within Green Ridge.

The adventure begins at the ranger station where you pick up a fall color tour that details the route and sights. (Be sure to use the mileage between points as a guide to the proper turns, because the criss-crossing of roads and trails is sometimes confusing.)

As soon as you drive up the narrow gravel road, the peacefulness and beauty of the forest overtake you. Fifteen Mile Creek runs with just enough water to make the rocks shine. The woods have turned the colors of lush sunsets: The maples offer reds and oranges, the tulip poplars show bright yellow, and the oaks, among the last to turn, glow from deep scarlet to purple. The leaves rustling in the wind create a delicate wave of sunlight and shadow that billows through the forest.

The forest surprises at every turn. At one point, tall pines and hemlock stand cool and majestic. Around the bend the road breaks into sunlight and crosses a clearing bordered with maples and poplars. The ruins of a 30-foot stone chimney rise in a clearing, and an abandoned railroad tunnel curves through a mountain. The old C&O Canal filled with leaves and still water parallels the road in places.

Along a steep and heavily wooded ascent, a wild tom turkey sweeps through the branches, his iridescent blue wings trailing his long black beard. A white-tail deer springs through the brush.

The road can be demanding: Its steeps ascents and descents require care and caution in a car. But its rewards are great. Because the ridges and valleys run parallel in this section of the Appalachians, some of the lookouts offer a seemingly endless vista of mountains all alive with fall colors.

If you can't travel the entire 25 miles, be sure to go the first seven, which take you past No-Name Overlook and Point Lookout. At No-Name, 4.5 miles into your tour, the Potomac snakes lazily in the distance, and you can see the hills of West Virginia. Point Lookout, about 2.3 miles farther, offers even more pastoral beauty. From this high ridge, the array of distant mountains and fields alive with color creates a quilt of uncommon beauty and texture. A hawk catches the wind, and the Potomac cuts a loop in the valley below.

At Banners Overlook, bordered by huge oaks and 18 miles into the tour, you arrive at the geographical heart of the forest. Stepping out onto the wooden balcony there gives you a feeling of floating above the mountain top, and there's a picnic table for your convenience.

When you resume the route, be careful. Do not continue past Banners Overlook; the directions can be misleading there. That road turns quickly into a steep hiking trail up the mountain and is not made for cars. Go back to the point where you made your turn to view the overlook, turn left and continue on the original route.

(One other word of caution about Green Ridge: It's bowhunting season there until Thanksgiving, and occasionally you'll see camouflaged hunters stalking deer. You should be perfectly safe driving this tour, getting out of your car along the road, and stopping at the overlooks; but straying from the road to hike the interior trails could be risky.)

For dinner on your way home, you might stop in nearby Hancock and try the Park-N-Dine Restaurant, a plain eatery adjacent to a gas station. It serves large portions of simple, country cooking at low prices.

GREEN RIDGE STATE FOREST -- Off U.S. 40, six miles east of Flintstone. Mailing address: Green Ridge State Forest, Star Route, Flintstone, MD. 21530. 301/478-2991. Open 24 hours. Free admission. No fee for camping but obtain permit at the ranger station.

To get there: From the Beltway, take I-270 to I-70 west to U.S. 40 west at Hancock. Continue on U.S. 40 west for about 20 miles until you see the forest entrance on your left. About 130 miles from Washington.

PARK-N-DINE RESTAURANT -- West Main Street, Hancock, 21750 301/678- 5242. Open 7 days a week, 6 a.m. to 10 p.m. THREE MORE FOR THE ROAD

If you'd like to drive off in some other direction, here are three other scenic outings you might try.

BOMBAY HOOK NATIONAL WILDLIFE REFUGE -- Smyrna, Delaware. In fall the sky fills with thousands of birds migrating south or arriving to spend the winter at this 16,280-acre wildlife preserve. From October through the end of November, the period when the waterfowl population is at its peak, Bombay Hook offers a gift to the eye. Set off against the fall colors of the trees are more than 50,000 snow geese, 40,000 Canada geese and 15,000 ducks.

The twelve miles of roads and the three observation towers treat you to such spectacular sights as hundreds of snow geese hovring like angels above a pond, or a phalanx of Canada geese flying in precise formation above a field bordered by the changing trees. Look carefully and you may sight the resident bald eagles, or the rare peregrine falcons cutting circles in the sky. Enjoy the sunset over the salt marsh, and watch the whitetail deer come into the fields at dusk.

BOMBAY HOOK NATIONAL WILDLIFE REFUGE -- RFD, 1, Box 147, Smyrna, Delaware. 19977. 302/653-9345. Open from dawn to dusk. The refuge, about a two-hour drive from D.C., is two miles north of Leipsic, off Route 9. The refuge office is open 7:30 a.m. to 4 p.m. Monday through Friday, and weekends from 9 to 5.

To get there: From the Beltway, take U.S. 50 across the Bay Bridge and stay on U.S. 301 north, to right onto Route 300 east to Smyrna. Turn right on Route 13 south. About two miles later, turn left on Route 12. The entrance to the refuge is about five miles ahead.

LOST RIVER STATE PARK -- Mathias, West Virginia. For a drive through sme of West Virginia's most enchanting terrain, travel the country roads of Hampshire and Hardy counties. Here, where the mountains rise their highest in West Virginia, you'll find views of broad valleys alive with reds, oranges and yellows.

For an easy but beautiful country drive, follow roads that trace the old Indian trails through the mountains and small towns -- many of which date to the Revolutionary War or the early 19th century -- to Lost River State Park. Its 3,700 acres include land once owned by General Lighthorse Harry Lee and offer trails for hiking and horseback riding, game courts and rental cabins. The park is also a good place to picnic and enjoy the scenery.

For dinner, drive to nearby Moorefield, chartered in 1777, for country cooking in the Old Stone Tavern, established in the mid-18th century. The McMechen House on Main Street, built in 1855, offers comfortable rooms furnished in period antiques.

LOST RIVER STATE PARK -- Mathias, West Virginia, 26812. Toll-free 1/800/624-8632. Open from dawn to 10 p.m. Free admission. About 120 miles (about 21/2 hours) from D.C.

To get there: From the Beltway, take I-66 west to Strasburg, to Route 55 west to Baker, West Virginia, to Route 259 to Lost River State Park.

To get to Moorefield, go north again on Route 259 to Baker, and then west on Route 55.

OLD STONE TAVERN -- 117 South Main Street, Moorefield, West Va. 26836. Open Tuesday through Saturday, 11 a.m. to 9 p.m.; Sunday 11 a.m. to 8 p.m. Complete dinners $3.50 to $14.75. 304/538-2186.

McMECHEN HOUSE -- 109 North Main Street, Moorefield, West Va. 26836. Five rooms, including two suites. Rates from $35 to $65 per night, including continental breakfast. 304/538-2417.

FRENCH CREEK STATE PARK, HOPEWELL FURNACE -- Elverson, Pennsylvania. For some history with your fall color, visit Hopewell Furnace National Historic Site, a restored 18th- century iron-making community surrounded by more than 7,000 acres of French Creek State Park.

Traveling these rolling hillsides of Pennsylvania's horse country will bring you through covered bridges, and past weathered barns and gentle farmlands. At Hopewell Furnace, where patriots forged cannons and rifles for the Revolutionary War, you can tour the restored and reconstructed buildings, including the cast house, where the molten iron was poured into molds; the tenant houses where workers lived; and the big house, where the iron works owner lived.

At adjacent French Creek State Park, you can stroll the scenic trails, picnic, fish and boat on the park's three lakes.

HOPEWELL FURNACE NATIONAL HISTORIC SITE -- RD 1, Elverson, Pa. 19520. 215/582-8773. Open 9-5 P.M. daily, no charge.

To get there: From the Beltway, take I-95 north to Route 272 exit, the second exit past the Susquehanna River bridge, and continue on Route 272 north until U.S. 1. Take U.S. 1 north to Pennsylvania Route 41 to Route 841 to Route 82 north. At intersection with Loags Corner in Bulltown, take Route 345 north to Hopewell Furnace. (From U.S. 1 on, this is the scenic route. About 140 miles (3 hours) from D.C. Special demonstration of moldings and castings of metals this Saturday, 10 to 5.

FRENCH CREEK STATE PARK -- R.R. 1, Box 448, Elverson, Pa. 19520. 14 miles southeast of Reading. 215/582-1514. Open dawn to dusk. Free admission. Camping sites available.

To get there from Hopewell Furnace: Return to Route 345 and go south for 1 mile to the entrance of the park.

COVERED BRIDGES -- For a guide to Chester County's 15 covered bridges, write the Chester County Tourist Bureau, 117 West Gay Street, West Chester, Pa. 19830. 215/431-6365.