STURGIS, S.D. (AP) — The Black Hills of South Dakota roared with motorcycles and crowds Friday as the annual Sturgis Motorcycle Rally kicked off, with mostly mask-less rallygoers packed shoulder-to-shoulder at bars and rock shows, despite a rise in COVID-19 cases in the state.

Organizers expect at least 700,000 people during the 10-day event that is a rendezvous for bikers, who connect over their love for motorcycles. For some, it’s a once-in-a-lifetime goal to make it to Sturgis; others faithfully make the pilgrimage year after year.

“It’s just a great big family atmosphere, everybody’s out here for the same purpose — we all love motorcycles,” said Aaron Harper. “If you’re a motorcyclist, you have to see it at least once in your life.”

Public health experts — and some locals — worry the rally will again play host to coronavirus infections, after hundreds of rallygoers were infected last year. Only about 46% of adults who live in the county that hosts Sturgis are fully vaccinated, according to the U.S. Centers for Disease Control and Prevention, compared with 60.6% nationwide. Virus infections are on the rise in South Dakota after a steady decline through the spring and early summer. The Department of Health reported a 68% jump in virus infections last week, with the highly contagious delta variant spurring a larger share of those infections.

Last year’s rally transformed Sturgis, usually a quiet community of under 7,000 residents, into a travel hub comparable to a major U.S. city. One analysis of anonymous cellphone data found that well over half of counties in the country were visited by someone who attended Sturgis. A team of researchers from the Centers for Disease Control concluded that last year’s rally ended up looking like a “superspreader event.”

This year, the rally is expected to be even bigger. The city held an opening ceremony Friday for the 81st iteration of the event — something it skipped in 2020 in an attempt to tamp down the crowds.

Jody Perewitz, the rally’s ceremonial grand marshal, said she was “ecstatic” to see how many people came for the opening ceremony. Motorcycles stretched for blocks as crowds strolled Main Street, the heart of the rally.

The biggest step city officials took this year to mitigate the risk of infections was allowing rallygoers to drink on public property, with the goal of spreading the crowds into the open air. Bars and food stalls that stretch for blocks also offer open-air seating.

“We’re out in the wide open,” said Pam Williamson, a rallygoer from Kansas who also attended last year’s gathering. “If you want to wear a mask, that’s your business. If you don’t, that’s your business.”

If last year’s rally was marked by defiance of coronavirus precautions, with T-shirts on sale that read, “Screw COVID. I went to Sturgis,” this year the pandemic appeared to hardly be an afterthought amid a crowd that embraces the risks and lifestyle of the open road.

“A lot of that, I don’t worry too much about,” said J.J. Vilella, who said he has not received a COVID-19 vaccine. “If it happens, it happens.”

The rally is known as a place where people let loose, strolling the streets in minimal attire and body painting. On Thursday, one woman walked through downtown with a goat on a leash. A man sat on a bench with a rifle as passersby smiled and nodded.

Health experts say big gatherings provide fertile ground to start a wave of infections. That didn’t seem to slow the Sturgis crowds.

“It’s in the back of your mind, you think about it a little bit,” said Harper. The Nebraska resident has not received a vaccine yet, but said he intends to. “But you’ve got to live your life and enjoy it and have fun still.”