Work on the Going-to-the-Sun Road has topped $110 million and there's still about $50 million to $60 million left to be completed, Glacier National Park superintendent Chas Cartwright said.

"I hope Congress passes a transportation bill this year," Cartwright said. "The end (of Sun Road construction) is in sight."

Bolstered by federal stimulus dollars, the alpine section of the highway could be completed as early as this fall or early in the summer of 2013.

Cartwright spoke at a question-and-answer forum at Grouse Mountain Lodge, in Whitefish. He said the park hopes to release a Sun Road corridor management plan in the next couple of months. The document will outline the park's future vision for the highway's use.

There are some problems, Cartwright admitted. Foremost is the park's public transit system. The system was designed to ease traffic on the highway during construction. An initial estimate expected traffic to be reduced by about 10 percent, but Cartwright guessed the actual number was far lower - maybe 1 or 2 percent.

The park's shuttle buses are also expensive to operate. The park takes $7.50 of every $25 entry fee to fund the fleet. That's about $800,000 annually, Cartwright said, but it's not enough. The only reason the park had enough funds to run the buses last year was because the season was shortened due to a record snowpack, he said. Future years could see a shorter season for bus service, he noted.

The buses are also creating more crowds in popular areas like Avalanche Lake and Logan Pass, he said. There's already plenty of private vehicles in both locations, but then the buses continually drop off hundreds more people at trailheads each day. It amounts to overcrowding in both locations, but Cartwright said there's no plans to expand the parking lot at Logan Pass.

Cartwright said he's also concerned about future funding for the bus fleet. Currently, a joint operating agreement with Flathead County helps take care of basic maintenance, but five or 10 years down the line the buses will need replacement.

Cartwright notes the current climate in Washington is not favorable for more funding for national parks. Over the past two years, Glacier Park has seen $550,000 in budget cuts, he said, and future budgets promise to be tight as well.

While bus use isn't what the park expected, they have proven popular, Cartwright noted. People have asked for more routes, not less. But overall, the park is spread thin, he maintained.

"I don't think we've been honest with the public on what we can and can't do," he said. "We like to do everything."

And that is proving increasingly difficult, he said.

"We can't try to do everything with significantly less money," he said. "The writing is on the wall - it's going to be really tight."

Other topics covered by Cartwright's talk included:

• The No. 1 complaint Cartwright receives is noise from helicopters and motorcycles. He said the Federal Aviation Administration has control over the skies above Glacier Park and to date, they have done little to regulate scenic overflights.

Cartwright said the park has simply asked operators in the area to observe the 2,000 feet above ground level guidelines when flying over the park. Some operators do, but obviously some do not.

As for motorcycles, a Park Service-wide standard needs to be put in place, Cartwright said, and when that happens, decibel meters could be placed at entrances. But that could take five or 10 years to implement, he said.

• The greatest threat to Glacier Park is aquatic invasive species like zebra mussels, Cartwright said. The park is considering installing gates at its boat launches. In the event of an outbreak at a lake outside the park, officials would consider closing down boat access to bodies of water in the park until the threat had been dealt with. Glacier Park already has mandatory boat inspections for watercraft entering its lakes.

• While the park is seeing lean times, Cartwright said he doesn't want to increase fees.

"I'm reluctant to raise rates," he said. "I want this to be an accessible park."

• The Many Glacier Road is in rough shape. An aquifer under the roadbed causes it to buckle, Cartwright explained. A fix won't happen soon - perhaps as soon as 2015, but later estimates are 2020.

• Rehabilitation of the Many Glacier Hotel is progressing. Work on the dining room is completed, and half the hotel will have new electrical wiring and other upgrades. Funding to complete the remaining work is in doubt, at least in the near term. Cartwright said he was hopeful the hotel will get back on a Park Service priority project list soon.