U.S. Marines in the Infantry Officer Course conduct fast-rope training near Yuma, Ariz., on March 26, 2015. (Lance Cpl. Jodson B. Graves/ Marine Corps)

In a historic first, the Marine Corps plans to assign a female officer to the infantry following her anticipated graduation from its grueling training program, service officials said Thursday.

The woman is a lieutenant. She and her male colleagues in the Infantry Officer Course completed an intensive combat exercise Wednesday at the Marines’ rugged training facility in Twentynine Palms, Calif., the final graded requirement of the 13-week program.

IOC, as it’s known among Marines, is considered some of the military’s toughest training. Typically, about 25 percent of students wash out.

The woman, whose name has not been disclosed, is the first female officer to complete the course out of three dozen to have tried. She is expected to lead an infantry platoon of about 40 Marines, a trailblazing role within an organization that has been criticized for its resistance to such change and for fostering a culture of misogyny. The service was engulfed in scandal earlier this year when more than 1,000 current Marines and veterans were investigated as part of an online network that shared, critiqued and in many cases ridiculed photographs of nude female colleagues.

The class will mark its graduation Monday, holding a “warrior breakfast” 40 miles south of Washington at Quantico Marine Corps Base, said three officials with knowledge of the development. They spoke on the condition of anonymity because the graduation has not yet occurred. All that remains between now and then is returning equipment used during training, and a few administrative tasks, they said.

The historic moment arrives nearly two years after the Pentagon lifted the military’s last remaining restrictions for women, part of an effort by Barack Obama’s administration to make the armed forces fully inclusive. Officials shared few details about the lieutenant Thursday, saying it is unlikely she will agree to do any media interviews, preferring instead to be a “quiet professional” and just do her job.

A description of the Infantry Officers' Course at the Marine Air Ground Task Force Training Command in Twentynine Palms, Calif. (U.S. Marines Corps)

The Marines first opened the Infantry Officer Course to women in 2012, on an experimental basis, allowing them to attempt the program as a part of military-wide research examining how to integrate all-male units. Thirty-two women tried the course before the research ended in 2015. None completed it.

Four others have attempted the course since the Pentagon opened all jobs to women in December 2015, including the lieutenant expected to graduate Monday. At least one of those four women attempted the course twice, but did not complete it.

The course requires both proficiency in the field, and the strength and stamina to carry equipment weighing up to 152 pounds. The school begins with a day-long combat endurance test that includes rigorous hikes through Quantico’s rolling, wooded hills, an obstacle course and assessments of skills like weapons assembly and land navigation.

Historically, about 10 percent of students fail the first day.

The new infantry officer will join a part of the military long seen as being critical of serving alongside women.

When surveyed in 2012, three out of four active-duty Marine infantrymen said they were opposed to full gender integration. Of the 54,000 Marines who responded, 90 percent of men indicated they were concerned about problems arising from intimate relationships between personnel in the same combat unit, and more than 80 percent said they were concerned about the possibility of false sexual allegations, fraternization and women receiving preferential treatment.

Marine Corps officials say those sentiments have waned since then, but it’s unclear how much — especially in light of the photo-sharing scandal that emerged this year. Gen. Robert B. Neller, the service’s top officer, has pleaded with Marines to be respectful toward women in the ranks, highlighting that some have died in combat. “I need you to ask yourselves,” he said at the time, “How much more do the females of our corps have to do to be accepted?”

Enlisted female Marines began joining the infantry in January. Senior leaders said last year that they were working to change the service’s culture in advance.

“There’s no doubt we’re leading cultural change,” Brig. Gen. James Glynn said then. “It’s not the first time that’s happened in the Marine Corps. We’ve been known to take challenges head-on.”

Other parts of the military previously open only to men have begun to integrate over the last two years. For instance, Army Capt. Kristen Griest was assigned last year as her service’s first infantry officer. In 2015, she became one of three women who completed the Army’s iconic Ranger School, a leadership course that focuses heavily on infantry tactics.

Women have not yet met the qualifications to take elite jobs in special operations, including that of Navy SEAL and Army Green Beret, though at least three have attempted the Army’s Special Forces Assessment Selection test.

Kyleanne Hunter, a member of the Pentagon’s Defense Advisory Committee for Women in the Services and former Marine Corps helicopter pilot, said that the Marines’ first female infantry officer will deal with two major challenges once she is assigned to her battalion. One will be winning over those under her command, Hunter said, and the second will be coping with outside attention and critics who want her to fail.

“I think people are rightfully excited,” she said. “She did something that is really hard, and it’s hard physically and it’s hard mentally. But at the same time, too much attention can take away from her operational requirements. Her first challenge is going to be to remain anonymous, for lack of a better term, and just do her job.”

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