IT'S E.T.B. tonight, kids; tomorrow we're climbing a mountain." Instead of the usual moans, groans and awww- moms, the family code-command for Early to Bed met with whoops, cheers and bright eyes. The call of the wild had struck suburbia.

Sugar Loaf Mountain is less than an hour's drive from Washington, possibly fewer than ten "are-we-there-yets." It's an ideal target for a first-time mountain-climbing experience, because one of the trails can easily be negotiated by even the wobbliest of toddlers given a helping hand or occasional hip-ride. Our expedition included two moms with four kids each, plus one kid's friend, ages two to 10, and everyone made it just fine.

Setting out at a decent 10 a.m. is perfect timing for a leisurely drive, the mountain climb and a luncheon feast at the summit before noon. If you drive north on I-270 toward Frederick, you can see Sugar Loaf Mountain rising above the plains like a big lump.

"Awesome," said the eldest.

"It's a mountain," said the youngest.

Sugar Loaf makes a sufficiently inspiring first impression whether approached from the north or the south. It's open year round, but it's best in late fall and winter, when you can catch a wonderful leaf show and less obstructed view from the peak.

Follow the signs to Sugar Loaf and drive up the mountain, first veering left at the lower parking lot, then going round and round to the uppermost level. (Sing "She'll be comin' round the mountain" to build up the anticipation/energy level of young hikers.) Just beyond the parking lot, yellow patches on the trees indicate the start of the walking path, called a yellow blaze trail by veteran trekkers. An easy half-hour walk, it winds through huge clusters of boulders strewn along broad, neatly laid-out timber steps.

A short, steep flight of stone-carvd stairs marks the last hurdle of the journey, and at this point it's important to rein in independent hikers inclined to race ahead of parents. While the view is breathtaking at top, so is the unguarded sheer cliff drop. (We narrowly avoided potential disaster thanks to the mountaintop presence of a mysterious pipe- smoking stranger, perhaps a guardian angel disguised as a solitary woodsman, who had interposed himself between our scrambling brood and the precipice. "I've been watching over them," he said with a serene smile, and walked away, leaving two tremulous moms breathing in a waft of cherry blend.)

To cap the adventure, a suitable spread is paramount. Our two families pooled picnics, thus offering my selection of P.B.&J. on white to my British companion's clan, while my own children far preferred her proffering of Swiss cheese and butter on oatmeal bread. Everyone wanted gooey chocolate Pinwheels, including the Big Boys, who had selected their own private dining rock.

The panoramic view also held some historical interest for the elementary-school ages. You could see White's Ferry, the spot on the Potomac River where General Robert E. Lee's army crossed on its unsuccessful march to isolate Washington. (A ferry now carries cars across there.) And on a really clear day you can see Bull Run to the southwest and the hazy Blue Ridge's line to the west. Why do they call it Sugar Loaf? Supposedly the shape of the mountain reminded Louis Michel, a Swiss who explored the area in 1707, of the conical "loaves" of sugar, pains de sucre, set up for winter storage in those days. "You mean it's not about pastry?" asked the kids, disappointed.

The descent can actually be the climax of the trip if you go via the gently sloping path, where youngsters can do what they wanted to all along -- namely career pell-mell, non- stop, hootin' and hollerin' all the way down the mountain, navigating some boulder obstacles and hurdling a few fallen logs

The foot of Sugar Loaf offers a pleasant denouement, with ruins of old battlements, dark dungeons and public restrooms.There are picnic benches where you can sit while kids romp on rocks. And if you're lucky enough to have made this journey with a foresighted Britisher, you can then sip hot, steamy tea from a reserve thermos, munch crumpets, chat of cabbages and kings and still make it home in time for the second half of the Redskins game. GETTING THERE --

From the Beltway, take I-270 north toward Frederick. Exit at Hyattstown onto Route 109 and go west about three miles to Comus. Turn right on Comus Road and go about two miles to the entrance of Sugar Loaf Mountain. Sugar Loaf -- owned by a private, non-profit corporation -- is open dawn to dusk, seven days a week. Admission is free.