DULUTH – Abe Pergament and his friends left St. Louis Park on Monday morning for an epic last-summer-before-senior-year fishing trip on a remote Canadian lake. When they got to the international border they waited, and waited, and waited.

"We were supposed to go last year, and that didn't work, Pergament said. "We were supposed to go early this summer, that didn't work. We weren't going to get stopped again."

The first day Americans could again cross into Canada for recreation, to check on property or reconnect with loved ones caused a traffic jam in International Falls as a miles-long line of cars and trucks — many towing boats or other recreational vehicles — waited as long as eight hours to get across the border. That was the longest reported wait time at any port of entry on the entire Canadian border on Monday.

"The urgency to get there on Day One is real for a lot of people," said Tricia Heibel, president of the International Falls Area Chamber of Commerce. "With the call volume coming through our office, we knew this was going to be crazy, and I think it's going to be for a while."

The line of vehicles that stretched past her office started forming Sunday afternoon as those who have been itching to get across the border since it closed to nonessential travel 17 months ago took the first opportunity to get across.

"In the summer, pre-COVID, we'd have these spikes and lineups would occur, but not this length of cars and not that length of time to cross," Heibel said.

Slowing the process down is a suite of new requirements for those entering Canada. U.S. citizens and legal residents must be both fully vaccinated and test negative for COVID-19 within three days to get across one of the world's longest and busiest land borders. Travelers also must fill out a detailed application on the arriveCAN app before crossing.

Jacqueline Callin, a spokeswoman for the Canadian Border Services Agency (CBSA), said the agency is adjusting staff levels to "minimize processing times and unnecessary delays at our ports of entry."

"Travelers should plan for the possibility of additional processing time when crossing the border due to the enhanced public health measures as CBSA will not compromise the health and safety of Canadians for the sake of border wait times," Callin said.

Troy Bauch was looking forward to getting back to Lac Seul, where his family has been going for decades. He bought a boat a few years ago and decided Monday was the day to drive up from Cornell, Wis., to get it in Canadian waters for the first time.

"We decided to go for it," said Bauch, who was traveling with his wife, Sharla, and dog, Aspen. "Sharla needs to go back to work in two weeks, so it's got to happen now."

But after four hours waiting in line in International Falls, Bauch grew nervous that their COVID-19 tests would expire by the time they could cross the border — they took the test on Friday, and it can be no more than 72 hours old.

"We're all real worried, since we have no choice but to sit in this line," he said. "This will be something we'll tell our grandkids about."

From Maine to Washington state, wait times were tame compared with the backup in Koochiching County. At other Minnesota crossings it was a relative breeze to get across.

"It hasn't been as busy as I'd hoped," said Lori Boomer, owner of Ryden's Border Store, which sits a half-mile from the international border at the northern end of Hwy. 61 on the North Shore. "A lot of people might be waiting to see how this plays out. It's a welcome sight and we're sure happy about it," since business has been down 90% during the border closures, she said.

What will really make the difference for Ryden's and many other border businesses is the U.S. allowing Canadians back in.

The U.S. has said it will extend its closure to all Canadians making nonessential trips until at least Aug. 21, which also applies to the Mexican border. But the Biden administration is beginning to make plans for a phased reopening. The main requirement would be that nearly all foreign visitors to the U.S. will have to be vaccinated against the coronavirus.

"We're grateful Canada has opened, and we're looking forward to the U.S. reciprocating that," Heibel said.

Bauch said that as heat and humidity pressed down on the line of vehicles, the travelers got to know one another as they crept along the road.

"I do have a little hope for humanity," he said, "because we had some nice people in the car behind us send their kids up to buy a whole bunch of ice cream. They went through the entire line offering everyone free ice cream."

The Associated Press contributed to this report.