DERBY LINE, Vermont (AP) — Canada lifted its prohibition on Americans crossing the border to shop, vacation or visit on Monday while the United States is maintaining similar restrictions for Canadians, part of a bumpy return to normalcy from COVID-19 travel bans.

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, and Canadian officials warn they won't sacrifice safety for shorter border waits. Travelers also must fill out a detailed application on the arriveCAN app before crossing.

On the first morning that U.S. citizens were allowed to cross into Canada again, it was slow going in the tiny border town of Derby Line, Vermont, where long stretches passed without any cars headed into downtown Stanstead, Quebec.

In Buffalo, New York, Lisa and Jim Docherty got COVID-19 tests at a pharmacy for their first visit to their Ridgeway, Ontario, cottage since the summer of 2019. The Hilton, South Carolina couple, originally from Buffalo, has had the cottage more than 40 years.

Lisa Doherty said she looked forward to "just mentally making sure everything’s OK.

“It’s just been a part of my life because my grandma had a cottage since I was 10, so just kind of a feeling like returning to normal," she said.

The pharmacy clinic was charging $140 for same-day tests and $125 for delivery of results in 24 to 48 hours.

“At this point, we’ll just do whatever we have to do,” Lisa Docherty said before heading in for a nasal swab.

By early afternoon, passenger cars were waiting more than an hour at the Rainbow Bridge to enter Niagara Falls, Ontario, from Niagara Falls, New York. There were no delays at two other western New York crossings, the Peace Bridge in Buffalo and the Lewiston-Queenston Bridge in Lewiston.

In Washington state at the Peace Arch Border Crossing and Historical State Park, three lanes of vehicles with Washington state license plates waited to cross the border Monday morning. Wait times were about 30 minutes at 11 a.m.

Wendy and Fred Chen, who live near the park said they went to the border to see the crossings were going. They said friends crossed at 1 a.m. Monday and waited two hours and that border agents thoroughly checked everyone’s test results, vaccination cards and identification.

They used to go into Canada weekly before the pandemic to enjoy city life in Vancouver, British Columbia, and take a break from their rural Washington state surroundings.

“It was so easy before,” Wendy Chen said.

The Detroit Windsor Tunnel reopened to no lines for vaccinated visitors to Canada. About two-thirds of its traffic halted during the pandemic, according to Neil Belitsky, chief executive of the tunnel, which runs beneath the Detroit River and handled about 4 million vehicles a year.

The U.S.-Canada border has been closed to nonessential travel since March 2020 to try to slow the spread of the coronavirus.

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.

But Canadians aren't waiting for reciprocal rules.

Garnet Health, an Essex, Vermont-based company that offers same-day COVID-19 testing, has seen the number of tests it performs more than triple in recent weeks. The increase coincides with Canada’s decision last month to drop a two-week quarantine requirement for its citizens when they return home from the U.S.

“I imagine once that border opens, we are going to see lots of people,” said Chelsea Sweeney, the company’s director of business development.

Joel Villanueva, owner of Primo's Mexican Grill in White Rock, British Columbia, about 2.5 miles (4 kilometers) north of the U.S. border, is more than ready for Americans to return.

“Let’s get this thing going,” he said. “A lot of our customers are from the United States, and we are literally minutes from across the border."

Villanueva said he supports people coming who are fully vaccinated and doesn't think there will be a rush of Americans initially.

Near the border in Washington state, Blaine Chamber of Commerce board member Carroll Solomon called the reopening a step in the right direction for businesses.

“For people who need to get up there (to Canada) for family reasons, it's wonderful,” said Solomon, who also volunteers at the Blaine Visitor Information Center.

Steve Blake, who lives in Stanstead, Quebec — just across the border from Derby Line, Vermont, — is hoping his siblings living in the United States will be able to visit Canada soon so they can hold a memorial service for their mother who died in early 2020. But given the requirements, he doesn't know how quickly that will happen.

“I’d like it to be sooner rather than later,” he said.

Sue Crumley of Abbotsford, British Columbia, crossed into the U.S. side of the Peace Arch to meet her family on Monday, including her 2-month-old grandson Silas, whom she had never met.

Canadians and Americans have been meeting at the park, located on the border in the U.S. and in Canada, during the pandemic without much interference from border agents.

Crumley said she knew the border was opening to Americans but said it was her understanding that her daughter and son-in-law would have to pay about $180 per COVID-19 test and opted to meet at the park instead.

Her granddaughter Sophia, 4, started running toward Crumley as soon as she saw her grandmother.

“We FaceTime for hours but it’s not the same,” Crumley said. “I couldn’t wait any longer.”