The sprawling campus of Arsenal Technical High School is an easy place to get lost. But if the rising graduation rate is an indicator, fewer seniors are falling through the cracks.

Two years ago, one in three students wasn’t graduating at the high school, which enrolls nearly 2,000. But educators at the largest high school in Indianapolis Public Schools have led a campaign to increase the number of seniors earning diplomas and boost the school’s graduation rate over the last two years.

And it’s paying off. Since 2015, the rate has risen by more than 15 percentage points, and last year 82 percent of the cohort graduated.

The impact of the improvements also extended beyond the school grounds. Arsenal helped push up graduation rates across the district to about 83 percent. The increasing graduation rate helped raise the school’s state letter grade to a C. More importantly, the gains meant an increase in the number of students earning diplomas, which will likely help them continue to college or earn better wages.

To be sure, high school graduation rates have improved across the country in recent years, in part because of a sustained effort to reduce dropouts. But Arsenal’s comprehensive approach to the problem could serve as something of a blueprint for other schools.

Their success has been so rapid that the question facing Arsenal staff now is whether they will be able to maintain the gains they have made — and if they can continue improving the graduation rate in the face of dramatic changes at the school and new challenges on the horizon.

The effort to improve graduation rates at Arsenal began two years ago, and was felt across the school, said Judy Carlile, the data and testing coordinator. Teachers were encouraged to build relationships with students and make sure they passed classes and earned credits.

Meanwhile, an eight-person graduation team focused on students who were at risk. When students had problems such as credit shortages, attendance problems, and failing grades, they received extra attention. And the team tracked down students who had stopped coming to school.

“There were a lot of kids who had just kind of fallen between the cracks,” said Carlile. “We just needed to bring them back together and say, ‘how can we get you where you need to go?’ ”

Graduation data revealed some obvious ways to improve. For example, the school had about five students a year who didn’t graduate because they failed gym, said Ross Boushehry, who is a social worker in his sixth year at Arsenal.

The school started offering ways for students to make up work, and they pushed them to get gym done in their first years of high school.

“We just thought to ourselves, this is ridiculous,” said Boushehry. “We have other, bigger issues to solve.”

Many of the students at Arsenal face serious barriers on their way to graduation. Last year, about 150 students were homeless, state data reported. Many students come to the school in their senior year with far fewer credits than they need to graduate.

Some seniors with credit shortages can make up the ground with options such as summer school or online courses. For others, the best option might be a program such as adult high school or job training, said Boushehry.

As graduation rates have risen across the country, experts have raised concerns that they may be inflated and graduates may not be prepared for college and careers. At Arsenal, there is mixed data on whether academic gains are on track with the graduation rates. The test that seniors take to graduate recently changed, and Arsenal has only seen a slight improvement.

In 2016, there was a jump in the number of students who received waivers to graduate without passing the state test. But in 2017 the graduation rate continued to rise while the waiver rate held steady.

Some students, like Breeasia Potter, had the academic skills to graduate but needed support. For most of high school, Potter had done well, racking up extra credits and taking honors classes. But in her senior year, life at home became so difficult, Potter said, that she thought she might drop out.

The staff at Arsenal kept her going, she said. Her counselor met with her every month, and when she missed school, one of her teachers would text her. She is now a student at Ivy Tech Community College with plans to become a doctor.

“I was in such a bad place that I honestly wanted to give up, and they made sure I didn’t give up,” Potter said. “I didn’t feel lost at all. I felt important at all times.”

The effort to improve Arsenal’s graduation rate also included a lot of work tracking down students who stopped coming to school but are still counted as part of the senior class.

The graduation team scoured the internet for students who had moved and hunted down records to show they were enrolled in an out-of-state school. They made home visits, spoke to their friends, and looked for them on social media.

“It’s detective work all the way,” said Melody Lundsford, the school registrar.

Yet for all that was accomplished over the last two years, it’s unclear whether the successes will be sustainable in the coming years.

Arsenal is changing. The school will likely see an influx of students in the fall, after the district closes three other high schools. Two leaders that spearheaded the effort to improve graduation rates at the school are no longer with the district. The graduation coach, Stephanie Weddle, left last summer. And the former principal Julie Bakehorn, who made increasing the schools graduation rate a top priority, took a job with the Tindley charter network last year after she was abruptly replaced as head of Arsenal.

The state is also in the midst of changing graduation requirements for students, and it could be increasingly challenging for the school to meet the standards. The Indiana State Board of Education approved controversial new “graduation pathways” in December that would add more to what students must do to graduate. Currently, lawmakers are tweaking the pathways system, proposing changes that could also make it more difficult for students to get waivers from the new requirements.

Given the potential changes to state guidelines, their jobs are going to be harder, said Carlile. But the graduation team will stay focused.

“We all know that we are here for the kids,” she said. “We want to put them in the best possible situation as they start to build their future.”