The rest of the country may be bracing itself for hard times as The Great Energy Crisis draws near, but in Montanna - where the coal is - they see things in an altogether different light.

With nearly one-quarter of the nation's coal lying under its vast eastern plains and the stiffest coal severance taxes of any state, Montana will be more than $20 billion socked away by the year 2010 as a result of the coming coal boom, financial experts estimate.

State officials happily concede that their predictions are on the conservative side and that Montana's coal windfall may be far greater. But in any case, Montana, which once could boast only of Mike Mansfield and the gizzly bear as its national show-pieces, now stands to become one of the nation's richest states.

"Some people," Gov. Thomas L. Judge said recently, "are calling us the blue-blue-eye Arabs."

The reference may not be too far of the mark. Montana has long had an unhappy history of being a badly misused one-industry state. Huge cooper mining conglomerates, which gradually fused into the Anaconda' Co., stripped away the ore and left a legacy of lung diseases, crumbling cities and abandoned gost towns.

"To my way to thinking, the Arabs are doing what they should have done long ago when they were exploited for years by the oil companies," said Michael Billings, state budget director.

Sitting in his office under the great copper dome of the state capitol, Billings said the same type of outside exploitation occured in Montana. "We've made some people in other states and countries extraordinarily wealthy from our copper but there's nothing left for us," he said. "We're not going to let it happen again."

Billing said the huge financial reserves will act as a buffer between the state and the coal companies in the future. Without it, he said, the coal industry might be able to force the state to relax its environmental regulations via threats to shut down and cut off tax revenues.

"With the tax money in the bank we can ride out the kind of economic catastrophes the copper companies used to threaten us with if they didn't get their way," he said.

Anaconda was purchased earlier this year by Arco, (Atlantic Richfield Co.). Arco also has large coal holdings in the Western coal fields.

The passage of a 30 per cent severance tax - a tax on coal when it leaves the ground - by the state legislature in 1975 made Montana is envy of officials in surrounding Western coal states and the target of bitter anger from some Midwestern utilities.

In Michigan, where the Detroit Edison Co. has a 26-year contract for 193 million tons of Montana coal, one Detroit newspaper editorialized after the tax was imposed that it was "usurious" and "fuel blackmail." Coal company lobbyists here predicted the tax would drive the coal mining industry to other states.

Despite the threats, there is no sign that the coal business is dying in Montana. Federal Energy Administration statistics released last month predict a jump in Montana's coal production from the current 26.2 million-ton level to 99.1 million tons annually in 1985.

The state had about 108 billion tons of recoverable coal - enough, said one state energy officials last week, "to last us a thousand years with some left over."

A dozen Eastern and Western coal states have severance taxes - taxes based on the value of the coal when it comes out of the ground - ranging from the lowest in Colorado (under one per cent, although the legislature is working to pass a slightly larger tax to Montana's 30 per cent.

Byron Dorgan, tax commissioner in North Dakota, which according to FEA projection, will be mining only slight less coal then Montana in 1935, said in a interview last week that North Dakoa Gov. Arthur A. Link made Montana's severance tax a model when his states's legislature began debate on a coal tax link last year.

A Democrat, compromised with the Republican-dominated state legislature to get a tax that will bring his state 65 cents per ton of mined coal and what is known as a "slinshot escalator clause" tied to any rise in the national wholesale price index.

"We didn't get a bad deal but it isn't as good as Montana's", said Dorgan. North Dakota's amounts to 25 per cent.

In Wyoming, which has a considerably lower severance tax than Montana, some legislators have indicated they would like higher coal tax revenues. Colorado's Gov. Richard D. Lamm has warned he may not sign his state's severance tax legislation because the amount is too low.

In the past, most slate coal taxes, including Montana's were based solely on a flat tax per ton rate with no escalator clause to cover rising coal prices. North Dakota, for example, had flat 5 cent-per-ton tax six years ago. By 1985, Dorgan predicted, North Dakota will get $1.72 for every ton of coal. Federal projections call for North Dakota to produce 96.9 millions by that year.

Despite the apparent economic bonanza from the coal tax, North Dakota officials said they fear the cost of coping with coal development in their state will take more money than the incoming coal tax revenues will provide.

North Dakota's coal has a low energy content, which means it is not practical to ship it long distances. That will mean, Dorgan said, that most of the coal will be processed within the state. If that happens, the state will bear the brunt of both the cost of the environmental impact of stripping and the social impact of huge new coal processing plants.

"We may get a lot of money," said Dorgan, "but it still isn't our propper share." The tax commissioner said he favors even higher severance taxes for North Dakota's coal. The total burden of the coal development should be passed on to out-of-state consumers through the increased price of coal, he said.

North Dakota has approved construction of one $500 million coal gasification plant in the rural farming community of Beulah and nearly a dozen more new coal-fired power plants scattered around the western portion of the state. Dorgan estimated the impact cost on the state for the Beulah plant alone would be "in the tens of millions."

Unlike North Dakota's, Montana's coal has a high enough energy content to be shipped out of state economically, and officials here have put strong pressure on coal companies to do just that. Montana thus would gain a huge income from severance taxes while holding down some of the more expensive problems caused by the construction of power plants and coal conversion facilities within the state.

Right now the approach seems to be working.

Last fall Montanans voted to put 25 per cent of their coal tax revenues into a state trust fund with the deposits increasing to 50 per cent by 1980. The rest of the coal revenue goes to what officials here call the "coal pie". The pie covers 12 different funds going to everything from schools to solar energy experimentation.