IF YOU DIDN'T get to go to summer camp when you were little, a reasonable facsimile for grownups awaits you in the foothills of the Blue Ridge Mountains down in Syria, Va. Graves Mountain Lodge offers the same sort of simple rustic life enlivened with swimming, horseback riding, hiking, softball and volleyball, even ping pong. You eat at the same sort of long communal tables and, if memory serves, it's rather the same kind of hearty food served in enormous plentitude.

The plus is the absolutely beautiful backdrop and the atmosphere, which is remarkably conducive to making friends. You can hardly remain strangers long while part of a human chain passing the mashed potatoes and applesauce to the kid at the end of the table. And the Graves seem to draw guests who don't mind sharing advice on the relative merits of mountain trails or where to find the best antiques. One fellow diner even took me down to view some newly-hatched towees she had discovered in a nest by her cabin.

This is not the place for you if you like a glass of wine and quiet anonymity. This is country life, elemental and hearty as a Big Mac, and it attracts young families and quite a few of the silver-haired set. "Teen-agers," says Jim Graves, "we're not real popular with them."

Nearby, in Washington, Va., a posh ski resort folded rather quickly and the locals, hearing Graves' blueprint for success, shook their heads. "It'll never work," they said, but they were wrong. Fifty percent of the Graves' business is repeat and now, even for November, reservations are tight. From Sept. 15th to the last week in October, the guests will be picking their own apples and the Blue Ridge foliage show will be at its height. Graves was close to fully booked for October.

Syria is a village of about 350 and the Graves name overshadows everything here. Jim Graves' great-granddaddy ran an ordinary and general store in this area, and a piece of the Shenandoah National Park is carved from land once belonging to the Graves family. Herbert Hoover's summer fishing retreat on the Raritan River was built on Graves' land. The canning factory in Syria belongs to the Graves so that they can shepherd the apples from tree to can all within the family. Their farm dominates the road beyond the four corners where the winter supply of galoshes has just arrived at the general store. But it's the Mountain Lodge that put Syria on the map.

"What does one do here?" I inquired from the man sitting next to me at lunch on a recent Saturday. He thought for a moment, fork suspended, and finally said that eating, to date, had been his main occupation and that of his family.

Eating might well be. Lunch was huge dishes of spaghetti, tuna fish salad, spinach, applesauce, apple butter, rolls, macaroni salad, ice tea and cake a la mode. "The food may not be gourmet," says Graves, "but we think it's pretty good." A lot of the guests seem to agree. On the porch after dinner the conversation was limited largely to (1) the view and (2) how much everybody ate. Gluttony is encouraged at Graves Mountain Lodge and the quantity is more remarkable than the quality.

Underneath each plate at lunch was a paper mat with a map of the countryside so, instructed by a helpful couple across the table, we set off after desert for a look at White Oak Canyon. A pretty falls was promised us at the end of about an hour's walk. We parked the car in the parking space a mile or two from the lodge and set off up the slopes of the mountain.

Madison County, where the lodge is located, has no access by car to the Shenandoah National Park, though all the foot trails eventually wind across its borders. The local story is that the late Sen. Harry F. Byrd Sr. of Virginia infuriated Franklin D. Roosevelt by voting against an issue dear to the president's heart, and that when the park was established the gates were located elsewhere in retaliation. Why did the punishment fall on Madison County? No one seems to know, but heads nod vehemently everywhere that this is so. Be that as it may, your feet will take you into this lovely wilderness from almost any point near the lodge.

White Oak Canyon Trail follows the Robinson River up a fairly gentle slope. On a Saturday afternoon, many a flat rock in the river serves as a seat for nature lovers who like to dally awhile to make their own music, to read a book, or simply shut their eyes and dream. Just sitting is a very popular occupation in Syria. The beech rocking chairs on the porch of the Mountain Lodge, for sale in a factory store in nearby Madison, are almost always occupied.

One of the nice things about the Shenandoah Park trails is that everybody you meet is an instant friend, inclined to stop to report on what lies ahead and to inquire about what you have left behind. Again and again we stopped to chat with fellow travelers along the trail, to compare notes about the incline and sights along the way.

Returning to civilization we paid a visit to the Graves farm across the road from the lodge. Large numbers of pigs were fruitlessly attempting to push their snouts through the fence to reach squash leaves growing in the neighboring field. We obliged with a few handfuls, inspected the cowbarn and returned to the lodge porch where Jim Graves was inviting his guests to pick their own peaches from a nearby tree. They were sweet and juicy, like the plums we tasted later when a man on a ladder hailed us as we walked by to ask if we had ever had one fresh from the tree.

Dinner was a repeat performance of excess encouraged, this time featuring country steak -- $9.95 if you were there only for dinner. This time we met a family who had been fortunate enough to secure accommodations in the tiny old farm house, built somewhere between 1780-1795, its foundations propped up casually on what looked like simple piles of stones and its ancient floors still beautiful after 200 years. They invited us in to see their room, which had a fireplace and a private porch and a nice rustic look. You might be lucky enough to get one of these rooms, which oddly enough are cheaper than the accommodations offered to us at the motel section of the lodge at $73 double occupancy, including meals.

Such prices seem high, when compared to rates at some of the delightful country inns in which I have stayed this season. Life at Graves Mountain Lodge is not cheap. Of the $73 charged for a double room, $35.10 is for the food, since the management expects you to eat your head off if you come only for the weekend. If you opt instead for a week's stay, the price falls to $400, full American plan, double occupancy, a saying of $111 over what it would be if you multiplied the single night price by seven. The theory is that, as on shipboard, the appetite flags after a day or two of overindulgence. t

Leaving aside the food, you are paying $36.90 for two in a room in the motel part of the lodge. Comparing this to the Country Inn at Berkeley Springs, W.Va. ($25 for a room for two), the Wayside Inn in Middletown, Va. ($30 for a double), and any number of others, it seems a bit inflated.

Sunday we had allocated for a look at the changing season in the park from Skyline Drive, so we left early for Sperryville, from which (no matter how Sen. Byrd voted) the park is accessible. But as the Cunard Line used to say of their transatlantic liners, getting there was half the fun. The Virginia countryside was a delight to the eye, dipping and rolling away from the road, inhabited by cows and country dogs and, at one point, a large white egret that rose from a stream and stretched his neck against the horizon as if he were modeling for our benefit.

Goldenrod and aster lined the sides of both Route 231 and the tiny country road (670) we took to reach it, wonderful rewards for shunning the turnpikes. Loaf along these country roads and you'll notice people in this part of the South have time to be friendly. We stopped for gas at a self-service station where the ancient attendant insisted on pumping it for us and afterwards washing our windshield. "My pleasure," he said when we thanked him. "I don't have nothin' much to do."

Sperryville is one of those little southern towns that lived through the Civil War intimately, hosting sometimes the Union, sometimes the Confederate army. Pope's Army of Viriginia was put together here from the nearby small towns -- young men from Fremont, Banks and McDowell. Today Sperryville is not much more than a crossroads bordered by old houses mostly in need of paint, many now reincarnated as antique shops.

Cheri Woodard's Faith Mountain Herbs & Antiques is one such, a shop with a pretty little herb garden in the rear. Cheri sells every variety of dried herbs for seasonings, decorating or planting, and lots of handsome baskets made in the Blue Ridge area. Upstairs in her store is everything from old 45 rpm records to beautiful patchwork quilts. Down the road at 1001 Main St., Mike Wyman offers elegant 18th- and 19th-century antiques, pressed glass, stoneware, chests and sivlerware. That Sperryville Emporium sells both antiques and country hams, and there are several other such stores in Sperryville. The nice thing is that most are open on Sunday morning, since the owners ususally live above their shops.

Stowing our purchases in the trunk, we entered the park at Thornton Gap entrance and turned south for lunch at Skyland, which I'd better remind you is open only through October. Right off its terraces the Appalachian Trail winds its way from Georgia to Maine and the pandorama of the Valley of Virinia lies beneath the dining room window. The overture of autumn color was just beginning then, but by now the oak, chestnut and hickory must be on their way toward explosive reds and yellows and the ash will be putting on its own purple show.

We lunched on southern chicken and ham and when we had finished drove to the tunnel overlook just between Thornton Gap and sat on the wall to admire. The mountains are lovely in any mood and the Skyline Drive goes through ancient granite rock over 1.1 billion years old. It would be a shame to hurry over it enroute back to the city.