The pandemic scattered college students from their campuses last year, leaving academic ghost towns across Minnesota. For local and federal officials trying to make sure every resident was counted in the 2020 census, the timing could not have been worse.

The push to get counted was set to kick off a couple of weeks after many colleges and universities shifted to online-only instruction, sending many students back to their parents' homes.

"If you could pick a perfect storm to happen, I think we might have had that," said Winona City Manager Stephen Sarvi. Student confusion amid the pandemic coincided with dropping enrollment numbers in colleges and universities.

For many Minnesota communities, college students make up a significant percentage of their population. If student numbers fell dramatically or if residents were missed in the latest census, that could affect the amount of state and federal aid a city receives over the next decade and change policy and planning decisions.

Winona, home to St. Mary's University of Minnesota and Winona State University, saw the second-largest drop in its overall population of any Minnesota city with 5,000 or more residents. The college towns of Crookston and Morris were also among the top five cities with the biggest declines.

The majority of Minnesota's college and university cities — from Duluth to Moorhead to St. Cloud — saw the number of people living in college dormitories plummet compared with the previous decade, according to census data released in August.

Census officials said colleges and universities were generally responsible for submitting the dorm numbers and they likely reflect falling enrollment and other changes, and were less likely to be affected by COVID-19. Minnesota Office of Higher Education data show the number of undergraduate and graduate students enrolled in postsecondary institutions dropped 23% from 2010 to 2019.

The pandemic's full impact on the census in college towns remains to be seen, State Demographer Susan Brower said. She said that when she thinks back to the days around the count, "My main concern, right at the top of the list, was college students. In particular, off-campus [students]."

Whether students living in off-campus housing were accurately counted won't be clear until next year when the Census Bureau releases population data by age, she said.

Last year, the bureau had detailed plans for on-campus promotions to ensure all students were counted before they left in the spring, said Adrienne Falcon, higher education coordinator for the Minnesota Census 2020. Then the pandemic hit, and outreach efforts moved online.

"The task was trying to track down students to where they scattered to tell them that they should fill out their form in a way that was like they were still living in Mankato or in Winona. And that seems like a virtually impossible task," Brower said. "Many of the colleges helped with communications and sent out e-mails to that effect, but who knows if those students were actually reached."

Morris City Manager Blaine Hill watched with worry over the years as the number of students at University of Minnesota, Morris dropped. He said he raised concerns about getting an accurate student count at several League of Minnesota Cities meetings before Census Day on April 1, when the Census Bureau kicked off its big publicity push.

The small city in western Minnesota saw its population drop and the number of dorm dwellers dip by 185 students, but Hill said that when he had a chance encounter with a vice chancellor of the Morris campus last month, "We both breathed a sigh of relief."

The city was on the brink of what Hill called "a magic cutoff." If it fell below 5,000 residents, he feared Morris could lose critical state aid for its road system. In the end, the census counted 5,105 city residents, down 181 from a decade before.

Not all cities with colleges and universities experienced a major change in the number of students in dorms. St. Joseph, St. Peter and Northfield saw their overall populations climb although the number of dormitory residents fell by just 2 or 3%. The cities are home to the private College of St. Benedict and Gustavus Adolphus, St. Olaf and Carleton colleges.

At Gustavus Adolphus — like many private colleges — the vast majority of students live in university residence halls. The school reported to the Census Bureau that all of those on-campus residents live in St. Peter, and it stressed to students not to allow their parents to double-count them after they returned to their hometowns during the pandemic, said JoNes VanHecke, the college's vice president for student life and the dean of students.

"Cities and counties rely on the census to make educated decisions about what they have in terms of resource need and what they might anticipate for their citizens, and our college students are members of those communities," VanHecke said. "And so it is important for the city of St. Peter and Nicollet County to be able to have a firm grasp on how many Gusties there are."

Arden Hills, home to Bethel University, didn't experience the trend seen at some other private colleges. Its dorm population fell 27% over the past decade, a decline officials attributed to enrollment changes and students choosing to commute from home. Hannah Bengtson, a junior studying nursing at Bethel, lives on campus but said she knows students who live in the Twin Cities and commute to save money on housing.

Bengtson was a freshman when COVID-19 arrived in Minnesota and scattered her friends across the state and country. She said she doesn't recall receiving any census information and isn't sure whether her family counted her as part of their household while she lived with them in Becker or whether the school reported she lived in Arden Hills — or both. In the chaotic early days of the pandemic, she said the census was not the top concern for students.

Arden Hills saw the largest drop in dormitory residents of any Twin Cities metro-area city. In Minneapolis, census data show the number of people living in university and college housing climbed by 8%. The student population at the University of Minnesota's Twin Cities campus has been growing by about 400 to 500 new freshmen each year, said Bob McMaster, the U's vice provost and dean of undergraduate education. And the U said it has added 1,432 beds of university-owned or operated housing since 2010.

The Minneapolis numbers contrasted sharply with dorm data of greater Minnesota cities, such as Duluth, which saw dorm populations drop 26%.

"I worry about the impact the pandemic has on really reflecting where people were and what they were doing and where they were living in that time frame," said Jeremy Leiferman, director of housing and residence life at the University of Minnesota Duluth.

Data editor MaryJo Webster contributed to this report.