The tiny town of Herculaneum, Mo., canceled the Fourth of July this year.

It’s saving its celebrations for the Super Bowl of celestial events — a total solar eclipse that will turn the Mississippi River-hugging burg of 4,000 dark for a full 2 minutes, 32 seconds on Aug. 21.

Scores of cities from Oregon to South Carolina are planted in the 70-mile-wide path of totality for the historic eclipse. With less than a month to go, they are watching with wary excitement, bracing for an onslaught of eclipse chasers and hoping for a solar system-sized economic boost.

“We’re doing a two-day festival prior to the eclipse,” said Herculaneum Mayor Bill Haggard, who is also overseeing the sales of city-stamped eclipse glasses, T-shirts and commemorative coins. “We’ve been working on this for a couple of years now trying to get the word out.”

A total solar eclipse last touched the U.S. in 1979, turning day to night along a path of a moon shadow that crossed five states. The Aug. 21 eclipse is the first coast-to-coast total solar eclipse in 99 years.

For many, it will be a once-in-a-lifetime experience, with hotels filling up more than a year in advance and reservations spilling over into university dorms eager to cash in on their location.

But economists doubt a significant economic boon will be felt in most areas.

Small towns are limited by how many people they can house, feed and entertain. At the same time, unlike a sporting event held in a specific city, the coast-to-coast eclipse spreads out spending with no one town as a focal point.

“Nashville is the largest city in the path, and it will see the largest impact because it has the biggest hotel capacity,” said Jeff Humphreys, director of economic forecasting for the University of Georgia’s Terry College of Business. “A lot of the smaller towns won’t have the infrastructure to accommodate big crowds so people won’t be spending a ton of money in them.”

Because the eclipse is happening in August when many families still are vacationing, Humphreys said there might be some “displacement” spending — where non-eclipse vacationers with plans to visit areas under the eclipse path will have to reschedule to other times.

Still, he doesn’t think anyone is adding significant dollars to their vacation budgets for the eclipse, meaning that money would have been spent on vacation-type expenses — hotels, gas, meals — anyway.

“The good news is, it’s an entire three-day weekend of spending,” Humphreys said, noting the eclipse falls on a Monday. “If it was midweek, it would make for a much smaller impact.”

In Rexburg, Idaho, officials are anticipating the town’s 30,000-person population to triple for the eclipse, but aren’t sure how much money that will bring to businesses.

Scott Johnson, Rexburg’s director of economic development and community relations, said every hotel within 100 miles is booked, and he’s heard of rentals going for as high as $1,500 per night.

“It’s amazing, the demand,” Johnson said. “It’s getting pretty crazy.”

Johnson said earlier this month that there still were open campsites, but private dormitories at Brigham Young University Idaho in Rexburg also are renting out rooms for eclipse tourists.

For a nightly fee of $500, and a two-night minimum, people can stay in an apartment at the Park View Housing Complex at BYU-Idaho. There is also a house with 12 twin beds, a game room, pool table, vending machines and a fire pit. But that’s going for $2,500 a night.

“We say a two-night minimum, but if people are willing to pay $4,000, we’re letting them stay the whole week for that one,” said Corey Sorensen, a Rexburg businessman and owner of the Park View apartments, about the home. “It gives us a good opportunity to show off Rexburg and BYU-Idaho.”

But Mary Eschelbach Hansen, a professor of economics at American University, said she’s pessimistic about long-term potential benefits for a town in the path of the eclipse. The best thing for communities to do is to gather data on who is visiting and how much they spend so they can generate a formula to estimate the impact of hosting events such as a youth baseball tournament or small festival.

“In some places, there may be a bump in sales tax revenue, but these places have got to be thinking about how they are going to control the crowds,” she said. “They will need people to direct traffic, have cooling stations, and first responders on duty.”

Those expenses could be more costly than the revenue that comes in, she said.

Johnson said Rexburg has limited the number of special events surrounding the eclipse because emergency officials were fearful they would be stretched too thin.

In Herculaneum, which is bisected by Interstate 55 south of St. Louis, Mayor Haggard is most concerned about traffic.

“The highway patrol is getting a little concerned,” Haggard said. “They asked me the same question about how many people we are expecting and I just said, ‘I don’t know.’ ”

If the sales of Herculaneum memorabilia are any indication, it will be a lot.

Haggard said online orders for solar eclipse glasses with the Herculaneum logo on them have been coming in from all over the country. He’s already shipped 8,000 to places as far away as Oregon, Massachusetts and Arizona, and is ordering an additional 3,000.

He’s not sure whether the popularity is because Herculaneum is an official NASA eclipse viewing city, or that he’s selling them for only $1 each.

“We’re not trying to make a killing off this stuff,” he said. “We want to make a little bit on stuff for our efforts, but we’re just hoping people will come here and say, ‘Hey, that’s a nice place, we want to go back there.’ ”