When customers telephone for reservations these days at the well-appointed Mount Airy Plantation restaurant in southern Prince George's County, their initial concern isn't table space.

"The first question they ask is 'How's the road?' " bemoaned innkeeper Frank Kulla, who with his wife Patricia restored the 18th century Calvert family hunting lodge to the tune of $2 million.

The inn may be fancy, but the roadway looks as if it was last serviced in the 18th century: deeply rutted, the mile-long lane quickly turns to muck in wet weather.

"It's like a giant milkshake from one end to the other," said Frank Kulla on a recent bad day. "Our cars are a mess. Our employes are complaining."

Inside, however, all is charm and order in the stately, 20-room mansion, which once was frequented by the old landowning families of southern Maryland and is now drawing some of their descendants.

Built in 1725, it was owned until 1902 by the Calverts, the original proprietors of Maryland under a charter granted in 1632 by King Charles I. Later it was one of several homes of Eleanor (Cissy) Patterson, editor and publisher of the old Washington Times-Herald.

Patterson willed it to a close friend and Calvert family descendant, Anne Bowie Smith. Smith and her husband were the last full-time residents.

Maryland bought the house and 1,000 acres surrounding it in 1973. After that it was vacant much of the time and began to deteriorate, much to the chagrin of the gentry in the nearby county seat of Upper Marlboro.

Mount Airy began to take on new life last year, when the state leased the house and 100 acres to the Kullas for 40 years.

The innkeepers, both well-traveled wine and food consultants, moved here from Connecticut. They opened for business Dec. 20 with a full-time staff of 12, including three graduates of the Culinary Institute of America and a maitre d' who also is an Episcopal priest.

The main dining area is a glass-enclosed atrium courtyard with a dozen tables covered with mauve tablecloths. There are five smaller dining rooms and, for overnight guests, two two-room suites priced at $195 a night. The price includes a breakfast of fresh-baked pastries, fresh orange juice, coffee and fruit.

"The first night, we had 100 percent occupancy," said Patricia Kulla. "Now, how many Ramadas can say that?"

With fixed-price lunches at $14.50 and dinners at $34, excluding wine and dessert, the Kullas have advertised in Washingtonian, Dossier and Country magazines. But until the entry road is fixed, Frank Kulla said, more advertising could backfire by attracting people who would only be repelled by the muddy lane.

Under the terms of a state contract, the road surfacing was to be completed in September. But inclement weather has delayed the work, state officials said.

The inn is "doing fine, except for the road," said Gary Yoder, chief of enterprise development at the Maryland Department of Natural Resources, which is leasing the property to the Kullas.

"He's had people come and say, 'My God, you need a tank to get back here.' "

"The dairy truck got stuck twice," said the Kullas' son Frank, 20, who helps his parents when he is not studying hotel and restaurant management in Rhode Island.

The Kullas must now meet the dairy truck at the main road, and guests occasionally have to be ferried from a nearby subdivision.

For those who plow ahead in their own vehicles, there is valet parking.

"Usually what happens is people see how bad the driveway is and turn around, but most people persevere," the younger Kulla said. "We do our best to make sure it's worth the trip through the mud."

Said his father, "If the weather is sunny and pleasant, we'll have 30 to 50 for lunch. If it's sloppy and miserable, we'll have a few."

On a recent day, the road was still soggy, but the skies were clear and seven lunch tables were occupied.

"A lot of Marlboro's here today," said Circuit Judge James Magruder Rea -- referring to people whose families, like his, have lived in the area for generations.

Among the diners were Bobby Clagett, an Upper Marlboro attorney, and members of the Bevard sand-and-gravel enterprise family.

Old-timers who used to visit Mount Airy "enjoy seeing it restored," Patricia Kulla said. "How could it not have been sad to think of the good times, good parties, and then see it go downhill?"

As she spoke, another reminder of the old days, the Marlborough Hunt Club, came into view. Barred from using the property when it was under direct state control, the hunt is once again welcome in the woods.

Led by huntmasters Patty Sasscer and Edward Coffren, the colorful hunters clopped by on horseback, trailed by barking dogs.

"The Marlborough Hunt hounds bounding past the French windows during the middle of the meal fully gives the proper effect of being in Marlboro country," Rea observed. ". . . The trouble with too many places is the Hollywood veneer. They haven't done that to this place."

The reality of state-owned property being used almost exclusively for the very rich might rankle some.

"It's one of the things that gave us pause," Yoder said.

Observed Madge Yewell, a Calvert descendant and daughter of the last private owner, "It's unfortunate that the average person won't be able to afford to eat lunch or dinner there. But perhaps they can tour the place and have a Coke. I hope that doesn't sound too callous."

Yewell, who is on the county planning board, and state officials like Yoder contend that without such business arrangements, the alternative often is to let historic properties fall further into disrepair. With scarce tax dollars going elsewhere, governments are increasingly turning over public land and buildings to private concerns, under the rubric of "adaptive re-use."

For Prince George's, which arranged the loan of state money for remodeling the mansion, there's more than money at stake. Of almost equal importance to some officials is the image of a county long looked down upon by some of its neighbors.

What Mount Airy means to Prince George's is not lost on the Kullas.

"It means Prince George's County doesn't have to run as stepsister to Montgomery County," said Pat Kulla. "We have a life style that can be just as agreeable and elegant -- if not more so."