More than 16,000 gamblers poured into the Mohegan Sun at Pocono Downs on its first day of business as the state's first casino, and in two days of operation, gamblers wagered more than $12 million and lost $1.26 million.

State officials, with their 55 percent tax on slots revenue, pocketed nearly $693,000 to use for property tax relief, aid to municipalities and help for the state's horse racing industry.

"It's obvious there is a great interest in gaming as entertainment in Pennsylvania," said Doug Harbach, spokesman for the state Gaming Control Board.

That interest was very evident yesterday at The Meadows in Washington County, where officials held a ceremonial groundbreaking for the newly christened The Meadows Racetrack & Casino. It is scheduled to open in May as a temporary gaming parlor with 1,700 machines that will spin, beep and flash for the thousands of slots players anticipated each day.

Officials of the track's new owner, Las Vegas-based Cannery Casino Resorts, expect the same eager public appetite for their machines as greeted Tuesday's opening of Mohegan Sun near Wilkes-Barre.

"We wouldn't be making this investment if we didn't expect it," said Bill Paulos, a principal in Cannery Casino Resorts and its parent firm, Millennium Gaming, which finalized the $200 million purchase of The Meadows this week from Magna Entertainment Corp.

The new owners say they are spending an additional $250 million on their temporary and permanent facilities, state gaming license, highway improvements and other costs.

The need to complete the sale of The Meadows has been a factor in slowing development of slots at the Washington County location, Mr. Paulos said.

The Meadows held the ceremonial groundbreaking for its temporary facility, but construction equipment has already been at work for weeks preparing the site adjacent to the parking lot and clubhouse.

The existing clubhouse is to be torn down and replaced in about two years with a larger, two-story facility with a 500-seat theater, multiple restaurants and bars, grandstand for racing and space for up to 3,000 slot machines.

In Luzerne County, Mohegan Sun officials opened their $72.6 million temporary casino promptly at 10 a.m. on Tuesday, and by midnight more than 16,000 patrons had poured in to use the 1,096 machines, far exceeding expectations.

Sun Marketing Director Jim Wise didn't have attendance figures for Wednesday or yesterday, but said, "We have been very, very busy. Customer response has been outstanding.''

The difference between the total amount wagered and the amount going to winners is called the gross terminal revenue. More than half of it -- 55 percent -- goes to the state, local municipalities, a special economic development fund, and horse owners and breeders. The other 45 percent goes to the casino owner, the Mohegan Tribal Gaming Authority, which also has a huge Indian-owned casino in Connecticut.

The state's take breaks down like this: 34 percent for property tax relief, 2 percent for the host county and 2 percent for the host municipality, 5 percent for a special economic development fund and 12 percent for horse owners, breeders and trainers.

Mr. Wise said one reason mentioned by many people coming to that casino is "they're tired of having to drive 3.5 hours in any direction to an out-of-state casino, and of having to take their business out of Pennsylvania. They seem satisfied with the quality of our operation."

The Meadows faces stronger competition, entering a market with two West Virginia racetrack/casinos nearby in Wheeling and Chester, and facilities also to open in or around Downtown Pittsburgh and at Nemacolin Woodlands. But Mr. Paulos believes his facility is well-situated to draw patrons.

About 400 new employees will be hired next year to staff the temporary facility, and an additional 600 once the permanent structure is completed in 2009.

Local, state and federal officials attending the ceremony at The Meadows hailed the pending development there as part of a wider economic boost the area is about to receive, with the Tanger Outlet Center, a new Hampton Inn hotel and other businesses to be built within a quarter-mile over the next year or two.

The first of about $20 million in highway improvements planned along Racetrack Road and at the Interstate 79 interchange is to get under way in March, Mr. Paulos said, to accommodate the anticipated surge in traffic.

Washington County Commissioner Bracken Burns said he likes the idea of millions of people with money in their pockets coming into the area, whether to gamble or take advantage of new shopping opportunities about to be developed nearby.

"We are very lucky to have the investment that is coming here," Mr. Burns said. "We anticipate 11 million people coming each year to this quarter-mile stretch [of new development along Racetrack Road] from this point forward."

Horse owner Neil Kochosky said he is looking forward to the better facilities and prize money that slot machine revenue would provide at The Meadows.

Mr. Kochosky, who owns 12 horses based at The Meadows, said the horsemen are eagerly awaiting improvements in the animals' living quarters and purses that will increase by 10 percent to 20 percent, as part of the revenue flow.

Higher quality horses are expected to arrive from out of state to compete at the track. Racing may have to shut down temporarily during construction next year, but no decision or timing of that has been announced.