There's the revolving-door student roster that reads like random pages of a school atlas: Jiang from China, Emma from Utah, Jose from Guatemala, Omar from Arizona.
There are the teachers, many of them transplants, including a dedicated Kurdish refugee who's helping dozens of students learn English, a job that would never have existed until now.
And there are rows of white trailers overlooking the football field, temporary homes for more than a dozen teachers — and for Foss, who's just a minute away from his office.
Like the rest of this town, Watford Elementary School has been transformed by the oil boom.
Families with young kids are constantly moving in, undeterred by the recent plunge in oil prices. The school's 700-plus enrolment is more than double that of 2011. Many of the newcomers are the offspring of riggers, welders, truck drivers, engineers and others lured from across America — and around the world — by the prospects of good jobs.
Their arrival has brought diversity to a school that until recently had virtually none.
"We have a world community within our own little school," boasts Foss, principal for the last three years. "The kids here can bring the globe to life, and that's kind of cool."
Watford Elementary draws on a school district that spans 1,679 square miles, more territory than all of Rhode Island. No longer a shrinking schoolhouse on the prairie, it's a bustling, ever-expanding melting pot. Since 2011, kids from all 50 states and more than 20 countries, including Yemen, Egypt, Russia, Pakistan, Mexico, India and China, have attended the school.
"A community that has been basically stable and white-bread now has every religion, every race, every cultural niche represented," says Gene Veeder, McKenzie County economic development director. "It's surprising how quickly it has become the new normal."
That "normal," though, comes with new strains and growing pains at the school. On any given day, teachers might find themselves hunting up warm clothes for a child arriving from the South, helping the family of a kid whose trailer has frozen water pipes or welcoming a student, knowing he might be gone in months. No one could have imagined any of this before the stampede to oil country.
"Ten years ago, you wondered what's going to be here — is it going to be smaller, smaller, smaller?" says Superintendent Steve Holen. "We were declining pretty rapidly. ... Now the reverse is true."
The school's enrolment has increased so quickly that before a new addition was completed, it was too small. To make more room, sixth graders were moved to the high school, which will be converted into a middle school next year. That's when a new $50 million high school is set to open.
The town's population has exploded at the same frantic pace, pushing up housing costs well beyond many educators' paychecks. (A two-bedroom apartment can go for $2,000-$2,500 a month.) Some teachers live in rent-subsidized apartments or 800-square-foot trailers — a temporary arrangement until they find permanent homes.
Foss will soon be leaving his trailer for the comfort of 2,000-square-foot home that recently arrived by flatbed truck. "I feel like I've been camping for three years," he says.
Despite declining oil prices, new students are still arriving. On one mid-February day, seven kids enrolled. Many folks here point out that Watford City is in the heart of the most profitable oil-producing area of the Bakken.
That prosperity has been a magnet for many newer teachers. The staff has more than doubled during Foss' tenure.
Melissa Rohrman, a first-grade teacher, traded the lush greenery of Fort Myers, Florida, for the ice-covered prairie — "not the prettiest place," she notes — so her husband could eventually start an electrical business. "I felt like I was coming to the Gold Rush," she says.
Charity Bratz left her teaching job in a remote Alaskan village, population 135, to be closer to family in Wisconsin. As a bonus, she also has some basic amenities she didn't have before — things like safe, running drinking water.
And Iva Dees left French Camp, Mississippi, when opportunity came knocking for her husband. He's making more money here driving a water truck than he did in his job hauling logs in the South. Dees, a 31-year teaching veteran, has embraced the change, if not the cold. She jokes that she returns to their former hometown on occasion "just to thaw out."
"I realize a lot of the teachers are as displaced as I am," Dees says with a laugh. "That gives us a little kinship. We are beginning to blend."
The students are doing the same, but it isn't easy because of the constant turnover. In January, for example, 45 kids enrolled and 18 left.
"You feel like you're running on a treadmill always trying to catch up," Foss says. "It's hard when you put in all the time and effort to educate these kids and three months down the road they're gone. You just hope you've made progress, but you don't know."
One boy, the principal says, enrolled in and left the school three times in one year. For another, Watford Elementary was his 11th school — and he was just a fourth grader.
Some kids leave when their parents are transferred to out-of-state oilfield jobs, others when the family's dreams of the good life in the oil patch don't pan out. Some kids who do remain struggle after being uprooted from their friends and the familiarity of their hometowns. Sometimes, living conditions make the adjustment harder if they end up in a crowded trailer with no privacy or place to study.
"The school is a little respite for them," says Bratz, who teaches second grade. "They feel like it's a safe haven."
Still, recreational activities are limited. Jonah Olson, an 8-year-old second grader and recent arrival from Wisconsin, says he likes the wide open spaces, but "they live pretty rough here. ... Everything's really hard here. Like you don't really get to do things."
School counsellor Alex Veeder, who attended Watford Elementary as a girl, works to smooth the bumpy transitions. "It's exhausting," she says of her job, handling everything from homesick students to those who don't have winter clothes or enough food. "Some of these kids have seen more than I have my entire life ... and they're only in first grade."
The school tries to ease the way for new families, offering its showers and laundry room for those who may not have ready access to them in trailer parks. It also provides food package on Fridays for needy students.
School officials emphasize the local housing shortage is a major hardship for families. Foss says about 40 per cent of the students are living in trailers or other arrangements considered temporary, which a federal law defines as "homeless."
But Alex Veeder remembers one boy who bristled at that label. "He said, 'People tell me I'm homeless. I'm NOT. I have a camper. And it's NICE,'" the counsellor recalls him saying. "He was offended."
As tough as it can be to start over, the new kids, she adds, blend easily with those who've grown up in the area. Just recently, she says, two girls joined her class and quickly ran off to play with another. "There's no, 'That's the new kid, let's NOT include her.' Everyone is the new kid."
Selam Ahmed tries to spread that message while teaching English to students who speak another primary language, most often Spanish. A smaller group of his students speak Arabic, Urdu, Chinese or Kurdish.
Ahmed tries to inspire the kids by telling them about his own tumultuous childhood. A Kurdish refugee, he was just a boy when his family fled on horseback, then crossed the Turkish border to escape harm during the Gulf War. They lost everything, including their home in northern Iraq, which was bombed.
When his family eventually resettled in North Dakota, Ahmed, then 11, spoke no English — just like some of the frustrated kids who sit by his side each day. He thinks his own success can serve as a guide.
"I want to be a role model," he says. "I want them to see they're not the only ones going through hard times, leaving behind family members, friends, homes. It's not the end of the world. We make the best of it, then we move forward. I remind them as much as I can that they're not alone out there. ... It doesn't matter if you have a mansion or if you have a trailer. It all depends on how you motivate yourself."
Cheri Puetz, a social studies teacher who left behind a 21-year career in Minnesota, sees a determination and flexibility among her fifth-grade students. They persevere, she says, no matter how many times they've bounced around.
"I'm impressed with how resilient these kids are and how well they've adapted," she says. "If the adults could learn from that, it would be phenomenal."
Sharon Cohen, a Chicago-based national writer, can be reached at firstname.lastname@example.org. National writer Martha Irvine contributed to this report.