Now is the time to begin planning spring and summer trips to the many parks within a few hours' drive of Washington.Whether you seek canoeing or birdwatching, hiking or hunkering down, primitive camping or comfortable cabins, company or isolation, it's all less than a tank of gas away.

Maryland's many state parks are a good place to start. A note to the state parks people will get you a general brochure plus folders on any specific park you ask about.

Twenty-one of those within 75 miles of the city have camping, and although first-come, first-served is the general rule, a few parks take reservations. Calling 301/768-0895 gets you the 24-hour recorded-message service covering campsite availability and general park information.

Only three Maryland parks -- Herrington Manor (190 miles from Washington), New Germany (164 miles) and Elk Neck (91) have cabins. So popular and so few are the cabins, which accommodate four to six persons, that reservations are awarded in a mid-January drawing.

Cunningham Falls State Park at Thurmont combines with neighboring Catoctin Park national recreation area and several private camps to offer a broad variety of outdoor experiences. Cunningham Falls' campsites are all on gravel pads in cleared areas, while Catoctin tries to maintain more natural settings. The parks even issue a joint brochure.

Besides the falls, Cunningham has a lake with a bathing beach and bath house; the lake is stocked to supplement the stream trout fishing, in which keepers must be 15 inches or more.

While Catoctin's primary purpose is to provide a buffer zone around the presidential retreat of Camp David, it has a lot to offer those of us who don't come by helicopter or Secret Service motorcade. A former Civilian Conservation Corps camp, the park has three group camps of hewn chestnut cabins, a dining hall and swimming pool. These are available to school and youth groups on the condition that they emphasize environmental education.

The family camp area is Owen's Creek, which like all national parks does not take reservations.

One of the group camp areas, Round Meadow, is also the site of the popular Folk Ways exhibit and demonstrations. The craft demonstrations include a blacksmith, shingle-maker, broom-maker and quitlters and special seasonal themes such as "sugaring off" maple sap. Some of the crafts are sold in the park's general store. Elsewhere there is a sawmill, operated during the summer, and a whiskey still (which now yields only distilled water).

Supplementing public facilities at Thurmont is the Crow's Nest Lodge, which has campsites, some of them streamside, on its 55 acres. You may rent cross-country ski gear for use on the park trails. In summer, horses rented at nearby Raven Rock may be ridden in the park.

In Virginia, two beach parks -- West-moreland on the Potomac River and Seashore on the Delmarva Penninsula -- are among the eitht Old Dominion parks that have cabins as well as camping. Both parks have hiking, boat ramps and nature centers.Westmoreland's cabins are for sleeping only, while Seashore's have kitchens. The cabins are a bargain, and fill up fast at prices ranging from $43.68 per week for two persont to $85.28 for four. Linens are not supplied.

Other nearby Virginia state parks:

POCAHONTAS (122 miles). Swimming, boating and fishing on Swift Creek Lake. Nearby camping and picnicking. Playgrounds, riding trails, wildlife exhibits and evening programs.

BEAR CREEK LAKE (159). Swimming, picnicking, fishing. Near commercial camping.

GOODWIN LAKE (158) In Prince Edward. Six cabins, swimming, boating and fishing in two lakes.

HOLLIDAY LAKE (169). Wooded campgrounds, lake beach and bath house, boating and fishing.

Shenandoah National Park is barely two hours away, which is a mixed blessing. It ranges from beautiful to breathtaking, but it also draws more visitors than any park east or Yellowstone, so reserve early and don't go expecting solitude between May and October.

Lodging at Skyland Lodge, Big Meadows Lodge and Lewis Mountain is operated under concession by ARA Virginia Sky-Line Co. Skyland and Big Meadows have dining rooms, and Big Meadows Wayside a lunch counter. Camping is available at Big Meadows, Lewis and Loft mountains and Matthew's Arm.

But while standing in line at an overlook for the view across the Shenandoah Valley you may find yourself reflecting that those ridges to the west are the George Washington National Forest, which is much bigger and permits wilderness camping and backpacking; you can even build campfires.

West Virginia sounds far away, but Cacapon State Park is just 90 miles (t'other side of the unincorporated hamlet of Oomps). Cacapon, set in rocky mountain terrain, draws 75 percent of its visitors from out of state.

Cacapon has no camping, but there are rustic and reasonably priced cabins plus a spacious and solid lodge spread over a knoll above an impressive golf course. A double room in summer is $20 a night (winter $18), a room for four $28 ( $24). In summer the Cacapon Inn has 11 rooms from $14 to $19.

Cabins at Cacapon are log or frame and classed as economy, standard or deluxe. Four-person economy cabins are such a marvel of compactness that you'll want to spend your waking hours outdoors, but rent for only $90 (Monday to Monday) from Memorial Day to Labor Day. All cabins may be rented by the day through mid-June.

Standard cabins have fireplaces and rent from $80 to $170 a week for two to six persons, from late April to early October. Deluxes have heat -- it can be cool in the mountains of an evening -- and are available year-round for $170 to $260 for four to eight persons.

There are cabins by the lake and others several miles up the mountain. The close-in ones are handy to the lodge's casual dining room and to the boat house and beach area. Outcroppings of rock around the lack make ideal perches for fishing (trout, bass, bluegills and crappie). Peddleboats and rowboats (inexplicably without anchors) may be rented at the boathouse, but find your own bait.

The park also has tennis courts and "Donald," who provides horses for $4 for a magnificent hour's trail ride.

Other West Virginia state parks:

BLACKWATER FALLS (185 miles). 25 deluxe cabins, 55 lodge rooms; tent and trailer campsites; restaurant, snack bar; swimming; sledding and skiing; rowboats and paddleboats; horseback riding; playground; naturalist.

CANAAN VALLEY (215). The park system's major winter sports area. 250-room lodge, 15 year-round deluxe cabins, 34 tent/trailer campsites; golf; tennis; fishing.

TYGART LAKE (200). 10 deluxe cabins, 20 lodge rooms, 40 campsites; restaurant; game courts; swimming, water skiing, scuba diving. Full marina.

LOST RIVER (115). Nine deluxe and 15 standard cabins, abundance of wildlife and scenic overlooks.k, restaurant; swimming; horseback riding; tennis; recreation building; naturalist.

PARKS IN MARYLAND. Information on the state's parks my be obtained from the Maryland Park Service, Department of Natural Resources, Tawes State Office Building, Annapolis 21401. A directory of private campsites can be had from the Maryland Association of Campgrounds, Route 7, Box 262, Chestertown 21620.

PARKS IN VLRGINIA. Cabins and campsites rent from Monday afternoon through Monday morning and may be reserved beginning April 2. Applications may be made by mail to Box 62284, Virginia Beach, or in person at Ticketron offices. Telephone or mail applications are not accepted by individual parks or state headquarters in Richmond; it makes the computer burp. To find the state or Ticketron terminal handiest to you, call free from any Virginia telephone (Monday through Friday) 1-800/582-8012. From out of state call 804/499-0853 or write the reservations center at Virginia Beach for a list. State parks: Division of State Parks, 1201 State Office Building, Capitol Square, Richmond 23219.

Private campgrounds: Virginia Campground Association, Route 1, Box 120, New Kent 23124.

Shenandoah National Park lodging: ARA Virginia Sky-Line Co; Box 727, Luray 22835.

Shenandoah National Park camping: Superintendant, Shenandoah National Park, Luray 22835.

George Washington National Forest: Federal Building, Harrisonburg 22801.

PARKS IN WEST VIRGINIA. West Virginia Department of Natural Resources, Division of Parks and Recreation, 1800 Washington Street East, Charleston 25305. Telephone (toll-free from Washington, Maryland, Virginia, Pennsylvania and Deleware) 1-800/624-8632 (Monday through Friday). Reservations may be made directly to individual parks, as much as 10 months ahead for out-of-staters.

Information on private campgrounds may be had from the West Virginia Campground Owners Association, 2228 East Paxton, Wheeling 26003.