Sometimes Zion National Park looks more like an amusement park, with so many visitors in Zion Canyon that you can't find a parking place.

The National Park Service wants to reduce the congestion, but it's hamstrung by the fact that Congress won't give it enough money. So rangers have been scratching their heads and mulling over ways to alleviate the auto crowding."The basic problem is that over the last 10 years, visitation to the park has increased by almost a million people," said Chief Ranger Bob Andrew. "It's 2.17 million this (past) year."

Within the Park Service's Rocky Mountain Region - Utah, Wyoming, Montana, South Dakota and North Dakota - only Rocky Mountain and Grand Canyon national parks had more visitors in 1988. Zion had more than Yellowstone, Grand Teton, Mesa Verde, Arches - the list goes on and on.

Since 1974, visitors have been increasing at about 7 percent a year. Commercial buses, often carrying foreign tourists, have stepped up their traffic by a stunning 30 percent a year in the past two years.

"It would appear it's going to increase by an even larger percent this year," he said.

Buses are a particular traffic headache because they take up as many as six car spaces in the small and restricted parking areas.

Zion Canyon, the main tourist attraction in the 146,597-acre park, is only seven miles long and usually about half a mile wide. At the widest point, it's only a mile and a half.

"There is simply not enough room to park all the vehicles entering the canyon, and congestion causes safety problems," says the National Park Service. "As a result, many visitors are unable to access popular natural wonders such as Weeping Rock and the Temple of Sinawava."

Andrew says that for seven months in the year, during the spring, summer and fall, the most popular vehicle turnouts and stopping areas in Zion Canyon are filled with cars. "People who wish to take the short hikes, people who wish to stop at view points and take pictures . . . are unable to do so because there's no place to park."

Traffic sometimes jams up to a standstill for 20 minutes to an hour because of the congestion.

More parking lots in Zion aren't the answer. The narrow canyon can't support any more, for one thing, and they're an eyesore.

Park managers want to implement a tram system. Visitors could voluntarily leave their cars at the entrance and jump aboard open-air vehicles that would circulate continually along the canyon highway. Maybe they would be like the double-deck, open-air buses at the San Diego Zoo, he said.

The trams would run every 15 minutes from 6 a.m. to 10 p.m. That would require 11 vehicles, allowing for a backup. An experiment last August showed that about 22 percent of the visitors would use such a public transport system. "It did reduce greatly the vehicle congestion at the major areas," Andrew said.

Park planners hoped to get the transportation system off the ground this year. But it turned out to be so expensive that they had to abandon the idea and shoot for the spring of 1990.

They are uncertain where money for the buses will come from. In fact, a questionnaire handed out to the public on parking and traffic problems had the largest blank space for: "Comments and thoughts on funding possibilities."

Zion is limited in raising money for capital improvements, because Congress has forbidden the park to increase its entrance fee beyond the $5 per vehicle already charged. With this money undoubtedly earmarked already, little leeway remains for such items as 11 open-air buses.

The problem is clear-cut, and professionals have thought it through to a good solution. Only it's not happening because of budget problems.

This is a world-class park, but the tourist experience is already being degraded.

National parks are among the country's greatest resources. Yet like other valuable investments, they require upkeep and protection.