Like many promising students from modest backgrounds, Nolan Arkansas started his college search with a major barrier: He was unaware of all of his options and undervalued his own potential.

Arkansas grew up on a Cherokee reservation in North Carolina, earning mostly A’s in school and developing some fluency in his tribal language. He figured he was bound for a public university in his home state or just across the border at the University of Tennessee. Elite private schools seemed inconceivable.

But a growing movement of nonprofit talent hunters and advisers is seeking to raise the ambitions of disadvantaged students and connect them with premier colleges, attacking a widespread problem researchers call “undermatching.” Some are helping eye-catching numbers of students land at colleges with low admission rates, including Georgetown University in Washington.

This movement found Arkansas one day in the spring of his junior year in high school. He knew instantly that getting into a program called Leadership Enterprise for a Diverse America was a pivot point. It was a door that would open more doors. He let loose a string of expletives.

“I don’t usually cuss in front of my mom,” the 17-year-old recalled, “but I couldn’t stop. . . . And then I was crying. I showed her the email on my phone. And she hugged me.”

Several months later, Arkansas was admitted to Yale University. He had made it from the reservation to the Ivy League.

Experts say for every Nolan Arkansas who is discovered and coached, there are many more low-income high achievers who still limit their search to the college down the road.

Most disadvantaged students with strong academic credentials “just don’t get why it is that they should be interested in applying to a selective college,” said Caroline M. Hoxby, a Stanford University economist. They take one look at the sticker price of private colleges, often exceeding $60,000 a year, and write them off. They don’t realize financial aid can put schools with small class sizes and high graduation rates within their reach. Instead, Hoxby said, these students focus on community colleges or others they see as accessible, inexpensive and ­convenient.

Hoxby and Harvard University public policy professor Christopher Avery found in a 2012 study that at least 25,000 low-income students a year, and probably 35,000, rank in the top 10 percent on SAT or ACT admission test scores and have at least an ­A-minus average. Most of them, Hoxby and Avery found, do not apply to any selective college — rendering them effectively invisible to admissions officers.

The Hoxby-Avery study rang alarms. It suggested selective colleges were overlooking legions of deserving students. That message resonated with critics who have long argued the admission system is tilted in favor of wealthy applicants who have easy access to test preparation, college-essay consultants and campus tours with their parents. Many colleges also give “legacy” admission preferences to children of alumni, another factor that favors the well-off.

But in the past five years, prestigious schools have intensified recruiting in low-income communities and expanded financial aid to lure students to enroll. Some have capped student loan obligations, and others have eliminated loans from aid packages, to reassure families worried about debt.

Some prominent schools have sought to boost the share of freshmen with enough financial need to qualify for federal Pell grants. Within the Ivy League, the share at Princeton University is 22 percent and at Harvard 17 percent. At less-selective public colleges, the segment routinely tops 40 percent.

To diversify further, the prestigious colleges want help. They can’t do it with “feeder” schools, public and private, that have supplied them for generations with students who are usually affluent. They must build new pipelines into communities long overlooked to find students from low-income backgrounds with high potential.

“They’re looking to programs like ours to do some of that vetting,” said Steve Stein, chief executive of SCS Noonan Scholars, based in Boston and Los Angeles. It helps 100 to 150 students a year apply to selective colleges.

QuestBridge, one of the largest pipeline programs, matches hundreds of disadvantaged students a year with 40 highly ranked colleges and universities. Others include Posse Foundation, College Advising Corps, ScholarMatch, College Possible and more.

“When you think about the scale of the challenge, it’s going to take a collective effort,” said Bryden Sweeney-Taylor, who oversees a remote-advising initiative for Bloomberg Philanthropies called CollegePoint. Begun in 2014, it links 15,000 low- to moderate-income students to advisers through computers and cellphones.

Leadership Enterprise for a Diverse America, with backing from private donors, including Princeton, provides intensive mentoring to 100 scholars a year. All are from public high schools. Ninety percent come from families with income of less than $66,000 a year, and the average family income is about $36,000.

Founded in 2003 and based in New York, the program recruits nationwide through road trips to rural towns, outreach to counselors and others, and word-of-mouth from older scholars.

“We’re looking for a cohort of super-bright young people who have tremendous leadership potential,” executive director Beth Breger said. The scholars, she said, are diverse, “representative of our country in many different ways” and “hungry for opportunity.” But in their upbringing they were not necessarily exposed to the full range of possibilities of higher education. “You cannot dream what you cannot see,” Breger said.

Georgetown University has enrolled 35 of these scholars over the years. Among them is Eriana James, 20, a sophomore majoring in African American studies from the south suburbs of Chicago. A first-generation college student, James said the program had a “huge impact” in spurring her journey to the prestigious Jesuit university in the nation’s capital.

“Where I’m from, a lot of teenagers my age do not think about such universities and colleges because we feel as if we will never get such an opportunity to attend,” James wrote in an email to The Washington Post. “We feel as if we are not enough. [Leadership Enterprise] had a different narrative for me. They highlighted that my potential and ambition overrides my racial and economic association.”

Casey Hammond, 20, met a Leadership Enterprise recruiter in 2014 in his home town of Hamilton, Mont., population 4,674. The encounter changed his life. The son of a single mother, raised by his grandmother, he grew up thinking his options were Montana State University or the University of Montana. “I knew that I probably should go to college,” he recalled, “but I didn’t know what that means. I didn’t know what I was going to do when I got there. I didn’t know how I was going to afford it.” Hammond, a scholar in the program, is a sophomore at Georgetown University with a double major in government and ­theology.

In the summer before their senior year, scholars are flown to New Jersey for a seven-week conference at Princeton that teaches them about leadership and the ins and outs of the college market, financial aid, admission test preparation, writing skills and how to apply to top schools. For Hammond, that trip in 2015 marked his first on an airplane.

Afterward, the program continues to guide scholars through college applications and enrollment. It writes recommendations for them and answers questions admission officers might have.

Results show inroads at some of the most selective universities.

Twenty-nine of 50 Leadership Enterprise scholars who applied to enter Stanford University in fall 2017 were admitted, the program reports. That admission rate — 58 percent — contrasts with Stanford’s overall rate of 5 percent.

Leadership Enterprise said admission rates for its scholars last year were 35 percent at Harvard, 47 percent at Yale and 59 percent at Princeton. At all three schools, the overall admission rate is in the single digits — a point of obsession for tens of thousands of applicants worldwide waiting on admission decisions this month.

“We’ve done well with them,” William R. Fitzsimmons, Harvard’s dean of admissions and financial aid, said of the program. “When we read the applications, and we know they’ve been through [Leadership Enterprise], we know they’ve been well taken care of.”

First, those students must get into the program. It’s not easy. The program gets about 1,250 applicants a year. (Admission rate: 8 percent.) The entry forms resemble college applications, and hopefuls can be spotted buzzing about their chances in the online forum College Confidential. Students must write essays, submit transcripts and test scores, and solicit a recommendation. They also must send family tax records to demonstrate financial need.

One day last month, three Leadership Enterprise recruiters huddled at their office in midtown Manhattan to screen applications. The program allowed The Washington Post to observe on the condition that students not be identified. The session felt much like a college admissions committee.

The stories that emerged were compelling, with an abundance of what admissions pros call “grit”: One student was being raised by her grandmother because her father had been deported. Another was the oldest of seven children in an immigrant family. A third was working 20 hours a week to help support his family. The recruiters dissected PSAT scores, grades, course selection, class rank, essays and potential.

Snippets from the discussion:

“Obvious admit, of course, but I do worry a little bit about are they going to let her come?”

“Her writing — she gives a lot of personal detail. But it lacks the next step: How these experiences have shaped her, who she is, what her goals are.”

“He writes so thoughtfully about his family. He’s amazing.”

“Two B’s in ninth grade — all A’s since then. He’s a strong writer, dynamic voice. . . . He’s proud of who he is.”

One of the three making these calls was Sayra Alanís, 24, a Leadership Enterprise scholar who graduated in 2015 from Rice University. Alanís grew up in Los Fresnos, Tex., a small town near the Rio Grande. A daughter of Mexican immigrants, she was a lover of rodeo and Friday night high school football. Her family was poor, she said, but she never went hungry.

Even after she was admitted to the program, Alanís had doubts. Her brother had to cajole her into boarding the plane from Houston to Newark that summer, telling her that if she didn’t, she would never leave and might regret it. “I had to run to the gate,” she said. “I almost missed my flight.”

It wasn’t easy to fit in at Rice. Few classmates shared her background. She sometimes felt like the only low-income people she knew on campus were other Leadership Enterprise scholars. But she earned a bachelor’s degree with a double major in Hispanic studies and women, gender and sexuality. Now, settled in Brooklyn and working near Madison Square Garden in program recruiting, she is paying it back.

“I constantly think about how different my life could have been,” Alanís said. “I wasn’t set up for success. And here I am, living my dream.”