The world's largest fire fighting aircraft touched down in Boise today giving onlookers a very visual demonstration. The Evergreen 747 Supertanker will be ready to hit hot zones this summer, but it won't come cheap.

Evergreen International Aviation's nationwide tour of their 747 includes just five states, and including Boise as one of the stops was no coincidence. Evergreen's primary customer is the U.S. Forest Service, which operates out of the Northwest Interagency Fire Center.

"Fabulous..." were the echoes from the crowd gathered south of the Boise Airport for a demonstration. The plane dropped thousands of gallons of water over sage brush in a water drop that took almost a minute to fully empty. But the size of the plane alone was enough to wow anyone looking to the skies over Boise today.

It's not often a 747 flies into the city. Short of a presidential visit, jumbo jets don't land here. That's partly why Ron and Ruth Mahurin drove almost two hundred miles from Slate Creek to see this supertanker do it's thing.

"We wanted to come and see how this plane worked and to actually see it in person," said Ruth Mahurin after watching the display and viewing inside the aircraft. But the 747 impressed more than just the public.

"What you have with one aircraft over the fire is the equivalent of seven of the old tankers," said Pat Norbury of the advantages the 747 brings to fire fighting. Norbury works with the Forest Service in Aviation Operations.

Current tankers used to fight fire hold only three thousand gallons. The 747 can hold more than 20 thousand thousand gallons of water or retardant. It can also make multiple drops in different locations on one load and it can carry both water and retardant in different compartments.

But some feared the giant plane was too big to maneuver over fires and fly low and slow over mountainous regions.

"None of that has proven to be true and this demonstration this morning conclusively showed that it's capable of the altitudes and the speeds that we could utilize it," said Norbury.

So could we be seeing the behemoth in Boise more often?

"I think what it's going to come down to is what is it going to cost and what is the value to us," said Norbury.

What it would cost to contract out the plane is still a tightly guarded secret, but Evergreen says getting to a fire at 600 miles an hour with seven times the capacity is worth it. The company devoted three years to developing the plane for fire suppression and other aerial application uses. They see it as being a tool for oil spill cleanup, chemical application, and even weather modification, broadening the market and, they say, possibly lowering the overall costs.

"We're very confident [in the plane's success] we've invested 40 million dollars of our own company's money," said Jim Dineen, Vice President for Evergreen Operations.

"You know we live in a part of the country where we have lots of forest fires and something like this could be fantastic," said Mahurin. And that prospect got people in Boise excited even if only for a day.

Dineen says the supertanker will be fully certified and ready to fly over fires August first and although the company has been in close contact with the Forest Service here to negotiate a contract price, no numbers are being released. Officials from Evergreen tell CBS 2 News they're keeping the numbers under wrap because they're still in the negotiating process.

However, you can bet that no matter the specific numbers, this addition would be the most expensive tool in the Interagency Fire Center's fire fighting tool box if a contract is reached.