If you're looking for a natural high, there are half a dozen lofty perches within easy reach of Washington.

Ranging from 500 to 3,300 feet, they all offer glorious views at the top of the trail, plenty of good hiking exercise and a taste of outdoor adventure.

One, a favorite of Thomas Jefferson's, sits above a great historical site; another puts you practically in the president's backyard at Camp David; and another is surrounded by back-country camping areas.

All can be reached and climbed on a day's trip or less, but some of the longer ones could easily slip into an overnight junket. Here goes: JEFFERSON'S ROCK, Harpers Ferry, West Virginia. Elevation 520 feet. Thomas Jefferson reportedly called the view "stupendous" and "worth a voyage across the Atlantic." You only have to cross the Potomac and Shenandoah rivers to reach Jefferson's Rock on the peninsular rise of Harpers Ferry. Start at the natural rock steps that lead up to St. Peter's Catholic Church. From there, it's a 10-minute uphill footpath to Jefferson's Rock. After your climb, take some time to explore Harpers Ferry National Historical Park, starting at the visitor center, open 8 to 5 year-round, where you can pick up a town map and a copy of a trail map. The town's restored buildings and daily craft demonstrations by people in period costumes bring the early 1800s to life. The spirit of John Brown provides much of the town's historical focus, and there's a museum and a commercial wax museum. (And if your climb didn't seem risky enough, Charles Town Raceway is just six miles away.) If you decide to spend the night, there are a few area motels, plus the prominently placed Hilltop House hotel, which offers another spectacular view whether you stay there or not. DIRECTIONS: Approximately 60 miles from Washington. From the Beltway, take I-270 to Frederick, then Route 340 west. Call the visitor center at 304/535-6371, ext. 6329. Expert help for the hiker is also available at the Appalachian Trail Conference, headquartered on Washington Street in Harpers Ferry. Open 9 to 5, Monday to Friday. 304/535-6331. SUGAR LOAF MOUNTAIN, Maryland. Elevation 1,283 feet. Sugar Loaf, which appears suddenly, rising out of the surrounding flat farmland, is the nearest peak for most Washingtonians, but proximity is only one of its pleasures. You start this ascent by car (motorcycles aren't permitted), stopping along the way at overlooks to sample appetizers of views to come. At the fourth view (elevation 950 feet), you leave your car to begin your hike. A concession stand is open "when the weather is nice" on weekends and holidays. There are also very rustic toilets and picnic tables. (Fires and camping are not permitted.) Dogs are allowed out of cars only on leash. On the way up, photographers should watch for bird's- eye views of climbers practicing rappelling. You may be lucky enough to get a shot of adventurers suspended by rope and hope. The trail is for the fairly well-conditioned, and is well marked by blue blazes. Winding from the parking lot counterclockwise, you follow a gentle loop to the top elevation, down, and then back around to your parking area. Sugar Loaf closes at sunset. DIRECTIONS: Approximately 33 miles from Washington. From the Beltway, take I-270 to the Hyattstown exit, circle under I-270 and go west 3.3 miles on Route 109 to Comus, then right on Route 95 for 21/2 miles to Sugar Loaf. Call 301/874-2024, 8 to 5, Monday through Saturday.) CATOCTIN MOUNTAIN PARK, Maryland. Elevation 1,670 feet. A seduction of the senses occurs on your approach to Catoctin, three miles after you have left the fast lanes of Route 15 in Thurmont. You realize it's time to slow down, smell the evergreens shadowing the road and listen to Big Hunting Creek. The National Park Service's visitor center at 900 feet elevation immediately beckons with abundant parking and clearly etched signs enticing you up no fewer than six trails. (More parking is available at the picnic areas higher up.) For this ascent, try the 11/2-mile route to Wolf Rock. The hike is somewhat steep and rugged -- park volunteer Bud Tegeler estimates that a well-conditioned person needs almost two hours to make the round trip. (From the summit, you can return on the same trail or loop back on another.) If you want to climb even higher, to 1,880 feet, you'll have to first be elected president so you can stay at Camp David, located in the heart of this park. Through October 23, weekend visitors can watch the Blue Blazes Still in operation, producing a very hard liquor. Samples won't be offered, and you shouldn't try to sneak a sip -- the brew is purposely laced with syrup of ipecac. If you're thirsty, better try the water at the visitor center, the camping areas or at the picnic areas in season. Grilling is permitted at the two picnic areas and dogs on leashes are allowed. No dogs are allowed, however, at nearby Cunningham Falls State Park; there you'll find a beautiful view of the falls, picnic areas and swimming and canoeing in a splendid lake. If you feel really energetic, you can save the entrance fee of $3 a carload ($4 for out-of-state cars) by hiking the 1.4 miles from Catoctin Mountain Park. Trout fly-fishing on a "catch and toss back" basis is available at designated spots along state-stocked Big Hunting Creek in both parks. A fishing license and trout stamp are required for anyone 16 or over. DIRECTIONS: Approximately 70 miles from Washington. From the Beltway, take I-270 to Frederick, then Route 15 north to Thurmont, then Route 77 west for three miles to the visitor center. The park is open 8 to 5 Monday to Friday (except Christmas and New Year's) and till six on weekends. 301/663-9330. For information on Cunningham Falls Park, call 301/271-7574. BRADDOCK MOUNTAIN, Maryland. Elevation 1,625 feet. So near to Frederick, yet so far away, Braddock Mountain is operated by the Maryland Park Service in Gambrill State Park. Open from 8 to sunset, it offers several well- marked trails (from one mile to almost five miles), including part of the Appalachian Trail. To reach High Knob at the summit, start at the parking area (about 1,300 feet elevation) on the "Blue Trail." This is the longest trail available (4.6 miles), and 20-year veteran Park Ranger George Hauver, Jr. estimates that it takes 21/2 to 3 hours to complete "although that could vary a lot, depending on the hiker." No dogs are allowed, even on leash (except for guide dogs for the blind). On your ascent through a forest of maple, birch, hickory and oak, you'll cross small streams, see one manmade "fire pond," and catch views of Frederick and Middletown from overlooks. At High Knob, there's a picnic area with grills (no other fires are allowed), drinking water and restrooms. It's not uncommon to see white-tailed deer and even a wild turkey; very occasionally you might spot a ruffled grouse. There's camping at the Rock Run area, but overnight hikers on the Catoctin Trail should check with the rangers' office about parking -- it's very limited and you may get towed if you don't have special permission to park. DIRECTIONS: Approximately 50 miles from Washington. From the Beltway, take I-270 north to Frederick, then I-70 toward Hagerstown. At the Middletown exit take Alternate U.S. 40 west for four miles to the park entrance on the right. 301/473-8360. BUZZARD ROCK, Massanutten Mountain, Virginia. Elevation 1,000 feet. Don't be misled by the seemingly gentle elevation of Buzzard Rock. Imagine instead a sheer cliff straight o "I've seen six-year-olds come down in fine shape while some teens were totally wiped out, so it's hard to tell who can do it and enjoy it." Much of the trail goes up at a gentle angle, yet the pitch near the top "will require you to take a break or two." This climb, as Kruszka puts it, includes "a right rugged patch of rocks." Your trail starts at the Elizabeth Furnace recreation area, where you'll find picnic tables, water, two covered shelters, grills and rustic toilets. (This picnic area is open 8 to 8, spring through fall, but winter access to the mountain is still possible by parking in front of the entrance.) Pets must be leashed. The "Big Blue Trail" takes you up alongside Passage Creek, a state-stocked trout stream (fishing licenses and stamps are required for Virginians and out-of-state visitors alike). Your trail will take you at times to 2,000 feet, across small streams, up some stone steps and to a number of overlooks. At the top of the mountain, turn north onto an orange trail (the markers have faded). From there, walk along the "backbone ridge" toward Buzzard Rock, where your view will be of Winchester, Front Royal, Massanutten Mountain and, to the east, the Blue Ridge. You can also look back toward Washington. But the real drama is looking down at the valley floor and the Passage Creek Gorge. Until the planned new route is constructed, you'll have to double back along the same trails to your parking area. Camping is permitted in the surrounding George Washington National Forest. Gas or Sterno stoves can be used there anytime. Camping is not permitted in the picnic areas, parking areas or municipal watersheds. DIRECTIONS: Approximately 75 miles from Washington. Take I-66 west to Front Royal, then Route 55 west approximately 9 miles to Waterlick. Then onto Route 678 about 3.5 miles to the Elizabeth Furnace Recreation area. 703/984-4101. OLD RAG MOUNTAIN, Virginia. Elevation: 3,268 feet. Part of the Shenandoah National Park, this strenuous hike, according to Potomac Appalachian Trail Club President Jack Reeder, can take five to eight hours. Glen Knight, a Park Ranger with 14 years' experience, backs up Reeder's opinion with the caution that the elderly or small children should not attempt this round-trip climb of more than seven miles. While pets on leash are permitted, it's extremely difficult to lift them up over some of the rocks along the ascent, he warns. Nevertheless, if you're able- bodied, Old Rag, which is open 24 hours, is a not-to-be- missed mountain. Two parking areas are available at 1,200 feet. The larger one is less than half a mile from the trail's start, the smaller right at the start. Free maps are available at park headquarters; more detailed ones can be purchased from the Potomac Appalachian Trail Club in Washington. However, trails are marked clearly enough that you don't need a map. Smacking of a true adventure, this trail doesn't pamper you with such conveniences as restrooms and drinking water. There's one picnic table and a fireplace in a shelter along the way (this fireplace and a few others are the only places where fires are permitted). Knight recommends going up the Weakley Hollow Fire Trail to Saddle Trail. At the top, you're rewarded by a panorama of the Blue Ridge across the west and of the piedmont region to the east and south. Then, round-trip under the summit for a return on Ridge Trail, looping back to the start. Back-country camping is allowed with a free permit from park headquarters, but you must be at least half a mile from developed areas and out of sight of trails. While fires are day's outing, many hikers stay at the very casual Graves Mountain Lodge, five to six miles away in Syria. Budget-priced meals are served family-style and are included in the room rate. While the lodge serves no liquor, guests are welcome to bring their own wine. When space allows, meal reservations are taken from non-lodgers. Book rooms in advance for weekends, holiday periods and during summer. DIRECTIONS: Approximately 80 miles from Washington. Take I-66 west, then Routes 29/211 west to Warrenton, continuing on 211 to Sperryville. Go south on Route 522 for three-quarters of a mile, then south on Route 231 for five to six miles (there'll be signs along the way), then right on Route 602 (which changes to 707 and then changes to 600) and follow the signs. For information, call 703/999- 2243.