Denver ? The backdrop of America’s bid for the 2016 Olympic Games might be the Golden Gate Bridge, the Sears Tower or the Los Angeles Coliseum – or none of these at all.

The U.S. Olympic Committee eliminated Houston and Philadelphia as candidate cities for the 2016 Olympics on Wednesday, leaving San Francisco, Los Angeles and Chicago in the running for what many consider to be America’s best shot in years at landing a Summer Games.

The three finalists, however, will have to make significant enhancements in their plans for the USOC even to bid on the 2016 Games, said Peter Ueberroth, the USOC chairman and the architect of the profit-making 1984 Games in Los Angeles.

“Right now, of the three cities that were selected today, there’s none that would have an acceptable program that we could take to the International Olympic Committee,” Ueberroth said. “It’s possible that none can get to where they need to be. It’s possible they all get to where they need to be. …

“It may be that one of these cities will drop out as we tighten the regulations, if you will, or the expectations.”

The three remaining cities will now have to finalize plans, including budgets, and present their bids to the USOC board of directors, which plans to decide by year’s end whether to submit a bid for the 2016 Games. If it does, it will pick a city by the end of next March. The IOC will select the winning site in 2009.

Other cities that have expressed interest in playing host to the 2016 Games include Rome and Milan in Italy; Madrid, Spain; Hamburg, Germany, and the Japanese cities of Tokyo and Fukuoka.

Led by Ueberroth, the USOC is taking a larger role in determining whether any U.S. city will bid for the 2016 Games. The failure of New York’s bid for the 2012 Games has been blamed in part on poor coordination between the city and the USOC.

Many people believe 2016 is the best chance for the United States to land a Summer Olympics in the near future. It is believed the IOC would like to put games in Africa and South America, two continents that have never hosted the games, in 2020 and 2024.

The U.S. has not played host to the Summer Games since the 1996 Atlanta Olympics. The 2002 Winter Olympics were held in Salt Lake City.