Students across Minnesota packed their backpacks and headed into classrooms Tuesday morning, kicking off a third school year altered by the COVID-19 pandemic.

Many students were wearing masks because of school district-imposed mandates, particularly in metro-area schools. Some entered classrooms where desks are still spaced to allow for extra distance, and some aren't in classrooms at all — opting instead for one of a growing number of online learning programs offered across the state.

But unlike last fall, the majority of students heading back for the 2021-22 academic year will be in person, getting face-to-face greetings from teachers and principals hoping for a less chaotic school year.

"By the end of the day, I just want to see smiles on the kids' faces," said Keisha Davis, who was starting her first day as principal of Hoover Elementary School in Coon Rapids. "With any first day, students, staff and parents are going to have some jitters. But I think this year, folks know more about what's happening and we know more about what works."

Davis' school is in the Anoka-Hennepin district, one of a handful of metro-area school systems that started classes Tuesday along with many metro charter schools and dozens of districts in greater Minnesota. While the Tuesday after Labor Day is the traditional start date for most Minnesota schools, the majority of metro-area districts, along with several in greater Minnesota, delayed their starts this year. That's because of the timing of Rosh Hashana, the two-day celebration of the Jewish New Year that this year began Monday evening.

Most of the state's largest districts, including Minneapolis, Rosemount-Apple Valley-Eagan and Osseo, will begin classes Wednesday. St. Paul Public Schools' first day of the year will be Thursday.

For students and families who were back to school Tuesday, feelings were decidedly mixed. While many found comfort in familiar routines, some expressed anxiety about everything from disrupted bus routes to rising COVID-19 cases in their communities.

Before watching their children head into Hoover Elementary, most parents held up their cellphones for a quick first-day-of-school photo. Others offered hugs and kisses and last-minute advice, including one mom who yelled, "Keep that mask up!" as her daughter was ushered inside.

Davis, the new principal, spent the morning directing cars into the drop-off zone and greeting students as they came off the buses. She joined a few children for breakfast and, without skipping a beat, grabbed a mop and cleaned up a puddle of milk on the floor.

"I'm just trying to figure out where I'm needed most," she said. "For some of these students, it's their first time back in a classroom in a long time so it's about reminding them about our routines."

Valencia Gary, a mother of three in Anoka-Hennepin schools, said this year feels like a chance to get her own family's routines back.

"I'm super excited to have them in school full time," she said. "Distance and hybrid learning was not always working for us."

Whougie Lo took a video as his 6-year-old son, Hero, headed into his new school. The family moved from Omaha, where Hero attended in-person classes all year. Still, Lo said he was grateful for the COVID-19 precautions at Hoover Elementary. Anoka-Hennepin schools is requiring masks for all students, staff and visitors in elementary schools.

"It's so important for him to have that social time alongside the learning, and he's looking forward to meeting new friends," Lo said.

At Twin Cities Academy on St. Paul's East Side, the pompoms were out and the upbeat tunes blasting as students made a long-awaited, full-time return to school.

Last year, the kids were limited to two in-person days a week at the charter school. Some, like junior Frank Buzzell, opted to stay online throughout all of 2020-21. He was a bit nervous, he said Tuesday, not because of COVID-19, but because of the work that lies ahead and decisions to be made: "Am I going to college or doing something else?" he said.

Twin Cities Academy staff members now operate under a vaccine-or-weekly-testing requirement like that adopted last week by St. Paul Public Schools, Executive Director Betsy Lueth said. She said 95% of staff at the sixth- through 12th-grade school have been vaccinated.

Outside, a couple of yellow buses straggled in about 10 minutes late, and students were cheered on by Karissa Gibson, dean of students. She was heartened there were no major delays, she said.

About a half-hour later, however, Emilie Claessens, a paraprofessional at the school, learned two of her children — a sixth-grader and a seventh-grader at the school — did not get picked up by their bus.

"We'll figure it out," she said.

School districts across the state are facing worse-than-usual shortages of school bus drivers. The problem has already prompted a lawsuit in Stillwater and forced Minneapolis and St. Paul district leaders to scramble before their school year begins.

In Duluth, which was also facing bus-driver shortages, fourth-grade teacher Pat Isbell said keeping kids safe is her first job, and teaching them is second. With COVID, "that hasn't changed at all," she said, and she's happy that Duluth schools require all to wear masks. When class resumed for part of last year, mask-wearing wasn't an issue for her fourth-graders.

"We were so excited to be together I think they would have worn a full bodysuit of armor," Isbell said.

Staff writer Jana Hollingsworth contributed to this report.