Days before a rare solar eclipse crosses the United States, state governments in its path are preparing to handle hundreds of thousands of visitors.

People are expected to flock to remote regions of the country for pristine views of the eclipse, activating emergency operation centers ordinarily reserved for storms, snow and forest fires.

Tourists are already congregating in rural Oregon, where a 30-mile traffic jam snarled a two-lane highway north of Bend on Thursday. The state expects as many as a million tourists over the next few days — the equivalent of 25 percent of the entire state’s population.

Gov. Kate Brown (D) said earlier this month she would activate the Oregon Air and Army National Guard to help ease traffic congestion. Extra ambulances will be at the ready, and the state has opened its Emergency Coordination Center to handle the influx. Brown will host troops of Girl Scouts for a watch party at the state capitol in Salem.
“State agencies, along with our local, tribal and federal partners, have extensively planned and are well-coordinated to make the 2017 total solar eclipse a safe and memorable event,” Brown said.

Tennessee’s emergency operation center will open in Nashville on Sunday, the state Emergency Management Agency said. The state Department of Public Safety has been preparing local governments for months, said Maj. Matt Perry, who oversees the Nashville District for the Tennessee State Patrol.

“We’ve been meeting, planning, talking, thinking eclipse for about a year now,” Perry said. “The magnitude of traffic coming into Nashville and Middle Tennessee and really across the state, we think it’s going to be like a crazy summer holiday travel [weekend] all wrapped up in one.”

Missouri government agencies have been working on plans to handle tourists since March, the state Department of Public Safety said. Missouri’s Emergency Operations Center opened Friday.

Jefferson City is the only capital in the country in the path of the totality — the phase of the eclipse in which the moon completely covers the sun — and non-essential state government offices will be closed Monday to free up parking spaces for the tens of thousands of visitors expected at the capitol complex.

The flood of tourists is already having an economic impact: Gas prices have spiked 9 cents per gallon in just the last week in Idaho, according to AAA. Idaho expects up to half a million visitors, hospitals are staffed at levels usually reserved for the busy July 4th holiday weekend, and the state’s Civil Air Patrol will operate extra flights to watch out for forest fires.

The city of Idaho Falls has set up a special phone line to answer resident and visitor questions about the eclipse. The line has attracted so many calls already that city officials scrounged up extra phones, to be staffed by off-duty fire fighters and police officers.

Cities and towns in the path of the eclipse are expecting an economic boom from tourists who come and stay overnight. Towns from Salem, Ore., to Idaho Falls and St. Joseph, Mo., expect more visitors than the number of residents. Grand Island, Neb., expects to generate $1 million in eclipse-related sales, according to the city’s Chamber of Commerce.

Just twelve million Americans live in the path of the eclipse totality, stretching from Oregon to South Carolina. Another 88 million live within 200 miles.