Two riverboat casinos in Tunica County, Miss., cashed in on their gamble to the tune of $140 million in just over a year. Now there are 14 would-be casino operators hoping to join them.

Figures collected by the Commercial Appeal newspaper of Memphis show that 1.7 million gamblers visited the Tunica casinos over the past year. Splash casino opened in October 1992, but the Lady Luck just opened in September.Casino operators say some 60 percent of their customers come from Memphis, where gambling is illegal. It's a 30- to 40-minute drive from downtown Memphis to the casinos.

A third Tunica casino is scheduled to open Monday. It is owned by Harrah's Casino Hotels, a subsidiary of the Promus Cos. of Memphis.

And on the horizon are five more operations that have announced plans but haven't yet applied for state gambling licenses.

Harrah's will be the 13th riverboat casino to open in Mississippi since August 1992.

Besides drawing most of their customers from Memphis, the Tunica casinos find many of their employees there, too. Officials in Tunica, which had an unemployment rate of 26 percent in January 1992, say just about everyone in Tunica who wants to work now has a job.

"The Memphis tourism and hospitality industry is about to become the stepchild to Tunica, Miss.," said Thomas Boggs, president of the Memphis Restaurant Association.

But economist John Gnuschke of Memphis State University said the casino market in Tunica will become saturated eventually and some of the rosier

financial projections will be proven untrue.

"The market doesn't exist here," Mr. Gnuschke said. "It doesn't exist in the Mid-South to support those kinds of investments. There are not enough buses in Memphis to carry people down there to spend that much money."

Tunica County, which had a total general fund budget of $3.5 million before Splash arrived, has collected more than $3 million in taxes and boarding fees

from the casinos.

City officials in Memphis long for a casino on the city's downtown riverfront and are leading efforts to legalize gambling in Tennessee. But gambling opponents vow a spirited fight.

The Tennessee Legislature is expected to consider a call this coming year to allow the state's voters to decide if their constitution should be amended.

The Tunica casinos are expected to play heavily in the gambling debate in Tennessee.

"I would not be surprised to see $600 million of casino revenues a year in Tunica County," said Bruce Turner, a gaming industry analyst with Raymond James & Associates of Fort Lauderdale, Fla.

No one knows how many riverboats can make a go of it in Tunica, but the casino building is expected to continue.

"Remember back in 1970, central Florida was a bunch of orange groves and Disney changed all that?" Mr. Turner said.

"I'm not saying Tunica is going to be the next Orlando, Fla. I think that's unreasonable to expect," he said. "However, the demographics, the transportation network, and the undeveloped nature of Tunica indicate it could be formidable over time."