HARDIN - Her shopping cart held all the ingredients for a backyard apocalypse: 54 fishing-bobber-sized shells loaded with flash powder, lunar-strength mini rockets and a showering fountain larger than a 30-pound dog.

Helen Deutsch of Ranchester, Wyo., had only started perusing the aisles of Baachachik Fireworks on the Crow Reservation. The brightly colored store is like Wal-Mart for pyros. The day before a long Fourth of July weekend, the store hummed like a beehive.

"The cops let us block off the street and then anybody who wants to do fireworks lights them off. The older people who don't do fireworks bring out their lawn chairs and watch the people who do," said Deutsch, who was eyeing a case of baseball-sized artillery shells dressed up in golden foil. "I was thinking about those, but I was a little afraid of what they might do."

Outside, cars began to envelop the building. There were vehicles from Washington, Wyoming, Montana and Idaho. It was 12:45 p.m., and things only promised to get busier as the Thursday workday wound down and the three-day weekend began.

"We save our change all year for this," said T.J. Woosley, of Bellevue, Wash., as his twin boys stuffed Roman candles in a shopping basket. "The boys roll it into nickels, dimes and pennies. We take it to the bank, and that's our fireworks and ice cream money."

This year, the Woosleys had about $200. Fireworks shows are ample around Puget Sound, but fireworks you can set off yourself are hard to find. So the Woosleys opt for Ten Sleep, Wyo., and swing through the Crow Reservation for a shopping experience they can't get at home.

"The best thing is probably these high-powered shells," Carter Woosley said - those, or ultra-slim Roman candles, which he and his brother, James, prefer to set off five at a time.

You can't get Roman candles everywhere. They're illegal off the reservation in Montana, as are the Tootsie Roll-sized firecrackers.

Most of the fireworks sold here, though, are of the ordinary variety, with 50 milligrams of pyrotechnic flash powder like fireworks sold off reservation. A lot of people stop and shop because they can handle the merchandise, which they can't do elsewhere, owner Matt Belue said, and credit cards are accepted.

Closer to Billings, sales were going well for George Reichenbach, who runs a stand outside the city limits about 3.5 miles toward Roundup. There are a couple dozen plywood sheds parked just outside the city limits selling fireworks. Business looks good this year, Reichenbach said, but the real measure of the season will come this weekend.

The hot items this year are 3-inch artillery shells that soar into the air and burst into color similarly to commercial fireworks. There's also a nine-shot mortar cake that shoots off artillery shells repeatedly, instead of one at a time.

"Business is probably as good as last year," Reichenbach said. "Some people say business is booming, some say it isn't. We'll know this weekend."

Police caution that fireworks can't be set off within Billings city limits. Thursday, officials closed the Rimrocks from Zimmerman Park to the base of Airport Road and Phipps Park to prevent fireworks-related injuries and fire. Barricades and signs have been posted. These areas will reopen on Monday.