Washington's tourmobiles, which carried 1.5 million visitors last year, have been purchased by District resident Thomas Mack, making the firm one of the largest minority-owned businesses in the Washington area.

Mack, who started his career giving tours at a Hollywood movie studio, has operated the tourmobile service since it went into full operation in 1969. Mack helped sell the tourmobile idea to the National Park Service in 1967.

Secretary of the Interior James Watt this week transferred the profitable tourmobile concession from the giant California entertainment conglomerate, Music Corporation of America (MCA), to Mack.

Athough the sale of the firm, known as Landmark Services Inc., was announced only this week, it took place Aug. 2, the day after the California firm also sold its concession rights at Mount Vernon Inn to the Mount Vernon Ladies Association, which owns the adjacent Washington mansion.

The sales price was not disclosed for either the tourmobile or Mount Vernon Inn. The popular tourmobiles this year are expected to carry a more than 1.8 million tourists, a record number which would bring in at least $3 million in fares. Both sales apparently were for relatively small sums, with MCA getting a percentage of the profits for at least the next 10 years, according to sources who asked not to be named.

Landmark Services has a tourist-season staff of 200. About 50 percent of the staff is black and half of Mack's supervisors are women, according to Mack.

Fares for tourmobiles on the Mall and in Arlington Cemetery and for Landmark buses to Mount Vernon are set by the Park Service to provide the concessioner with a reasonable profit, although the amount is not made public. The government gets a franchise fee of 4 percent of Landmark's gross receipts.

Mack is as reticent about describing himself as he and MCA are in discussing tourmobile finances. In an interview, Mack said he was a bachelor who likes golf and lives in a condominium near Connecticut Avenue and Chesapeake Street NW. He declined to give his age and would say little about his past except that he was born in Lincoln, Tex., the son of a farm laborer. He attended several colleges before graduating from California State University at Los Angeles in 1960. He got his tour guide job at Universal Studios in 1965.

"I took tours and talked about stars like Rock Hudson, Paul Newman, Marilyn Monroe and Marlon Brando and then -- it was still a pretty small operation -- I was made director of personnel and asked to prepare a prospectus for operating a tour bus service in Washington . . . because my boss had heard I was interested in writing," Mack said.

After he wrote the prospectus, MCA sent him to Washington in 1967 to present it to the Park Service, which was considering providing a tour bus operation and had experimented the year before with a surplus World's Fair "minitrain" on the Mall. At 10 cents a ride, it had proved extremely popular.

"We won the bid" over D.C. Transit, Washington's privately-owned bus company, and several other local and out-of-state firms, said Mack. "MCA officials said, why not go back and run it. It was an offer I couldn't refuse."

Landmark Services began with three tourmobiles, charging $1 a day for unlimited rides on the Mall. But the tourmobiles had barely started before they were stopped by a D.C. Transit-Washington Metropolitan Area Transit Authority suit challenging Interior's right to operate a bus service on the Mall.

Two years later, after conflicting lower court opinions, the Supreme Court ruled Interior's authority on the Mall dated from 1898, long before Congress gave WMATA authority over public transit here.

Landmark now has 29 tourmobiles of assorted sizes for use on the Mall and in Arlington Cemetery, and four large buses used for Mount Vernon tours.

Fares have increased to $5.50 for adults for the Mall and cemetery, which Mack and MCA have insisted is low compared to other tour bus fares here and in other cities. Mack said this week he soon may request an additional fare increase from the Park Service because inflation is raising Landmark's costs.

Mack said he is planning few changes in Landmark Services but is discussing with the Park Service a possible tour bus route to the Frederick Douglass home in Anacostia. But most of his discussions for the past 15 months have been over the purchase of his prized Landmark Services.

"And when things get tense I go out and walk around Hains Point" in the jogging shoes he keeps under his desk at Landmark's new $1.3 million garage headquarters next to the Hains Point tennis courts. "It's a nice three-mile walk," he said.