"New courses should be 100 percent ADA-compliant, or at least have a significant portion of their course accessible," said Swanlund, whose year-old indoor course offers total access to the disabled. "However, I think it will be a tremendous burden if all existing courses are required to make the change. These courses are absolutely not high-profit, so we would see a loss of courses if these rules take effect."

Miniature golf courses are among the millions of businesses and other public facilities that would feel the effects of regulatory changes under the Americans with Disabilities Act, the milestone 1990 civil rights law that prohibits discrimination on the basis of disability.

The proposed rules address a wide range of facilities -- including access to courthouses, drinking fountains, amusement park rides, stadium and theater seating, fishing piers, boat slips and bowling lanes -- and establish specific requirements for qualifying accessible designs.

The modifications could make a major impact on entertainment-heavy Las Vegas, where hotel-casinos built theme parks, concert venues, bowling alleys and other attractions to compete for a share of the 40 million tourists the city hosts annually.

A spokesman for MGM Mirage said Friday that it's too early to tell how the potential changes would affect the resort operator, which owns the Adventuredome Theme Park inside Circus Circus, the Shark Reef at Mandalay Bay and five Cirque du Soleil theaters on the Strip, among other attractions.

"We're currently monitoring and assessing the proposed changes to ADA and how they would impact our operations, if at all," said company spokesman Gordon Absher.

Harrah's Entertainment and Boyd Gaming Corp. didn't comment on the changes by press time.

The regulations proposed by the federal Justice Department are drawing intense scrutiny from businesses that foresee a financial drain and disability rights advocates who say they are long overdue and don't go far enough. Both groups say they want more clarity.

"We have a very mixed sense of what's happened," said Curtis Decker, executive director of the National Disability Rights Network. "They left a lot of things unanswered."

Costs to 7 million affected businesses plus state and local government agencies would total $23 billion over 40 years, according to the Justice Department. But they'd also realize billions from being more accessible to disabled customers. The Census Bureau says there are more than 51 million disabled Americans, representing 18 percent of the population.

The rules would apply to new businesses and facilities and to alterations of existing ones. Businesses also would have to remove "readily achievable" barriers -- changes that don't require a lot of difficulty or expense. The government published the proposal last month. Final regulations could take effect next year, after a period for public comment.

Bruce Young, a local shareholder with national law firm Littler Mendelson, said the regulations would virtually guarantee a flurry of fresh lawsuits from advocates on both sides of the issue, as consumer groups and business associations alike test the boundaries of the new rules.

"Anytime you have this type of broad, sweeping regulatory change, both sides have an incentive to go out and find what exactly the changes mean," Young said. "They'll want some concrete rulings from the courts."

The regulatory alterations come as Congress weighs legislative changes to the ADA that would broaden the definition of disability for employment purposes, Young noted.

"It's kind of a double whammy," he said. "A lot of people are looking at this as a wholesale revision and expansion of what the ADA is going to be."

Those revisions couldn't come at a worse time for businesses, said Gregory Kamer, a partner in the Las Vegas law firm of Kamer Zucker Abbott and an attorney who counsels corporate clients on ADA compliance.

Add the potential costs of the new rules to high energy prices, a rising minimum wage and a struggling economy, and some businesses could lose what little profit they already earn, Kamer said. And though it's important to accommodate the disabled, he added, it makes little sense to do so at the expense of entire businesses.

The regulatory changes could also upset a delicate equilibrium forged over nearly two decades of ADA law.

"There are some frivolous (ADA) suits, and there are some legitimate suits," said Kamer, who defends businesses against ADA claims. "It seems the law as it has existed has stricken a fine balance. We may be upsetting that balance with legislative or regulatory changes to a point that's unnecessary and harmful. When the pendulum swings too far in the way of the disabled, you're going to find operators pushing back."

Not all operators foresee a need to push back.

Thousands of gallons of water pulse through cascading waterfalls and rapids at Adventure Mini Golf in Lake Worth, Fla. The course, which covers about an acre, features different elevations with two sets of stairs connecting them.

When people ask whether it's accessible for the disabled, owner Jerry Doser says he jokingly tells them, "No, but I'll paint some lines in the parking lot and put some cups out there and then you can play."

"But who wants to pay to play that?" he adds.

Swanlund, the King Putt owner in Las Vegas, agreed that making his course 100 percent accessible did slightly reduce "playability."

"The course isn't as interesting as it could have been had we not considered the ADA rules when we were making it," he said.

But Swanlund said he believed in the importance of offering access to all.

"We didn't want to exclude anybody," he said.

Both sides said much uncertainty remains and are asking the Justice Department to clarify some points before releasing the final rules.

"Picture yourself as a small- to medium-sized business saying to yourself, 'What is this all about? What changes do I need to make?'" said Randel Johnson, a vice president at the U.S. Chamber of Commerce. "Figuring out the changes you may need to make or not make, that's an enormous amount of time and legal fees."

Contact reporter Jennifer Robison at jrobison@reviewjournal.com or 702-380-4512.

The Associated Press contributed to this report.