The three remaining women attending Army Ranger School as part of an assessment of how female soldiers should be more fully integrated into the service have passed a major hurdle, completing the first of three segments in the course and moving on to its Mountain Phase.

Army officials announced the result Friday, saying in a news release that 158 men and all three women will move on to tackle the next portion of Ranger School at Camp Merrill in Dahlonega, Ga., about 65 miles north of Atlanta, beginning Saturday. It was the third and final attempt for the remaining women, who had failed the initial Darby Phase at Fort Benning, Ga., twice before. A total of 362 men began the course with them June 21.

The female soldiers moving on raises the prospect that at least one of them may become the first female graduate of Ranger School. Typically, about 42 percent of service members who attempt the Ranger Course eventually pass, but the graduation percentage jumps to more than 75 percent for those who make it through the Darby Phase.

“I had the opportunity to observe this class during their training and was especially impressed by the professionalism and extreme competence of the Ranger instructors,” said Maj. Gen. Scott Miller, commanding general of the Maneuver Center of Excellence at Fort Benning. “Without a doubt, Ranger School is the most physically and mentally demanding course in the U.S. Army. I have complete admiration for the soldiers, other services and partner nations who volunteer to attend and work to earn their Ranger Tab.”

The Mountain Phase is 20 days long, and includes intensive training and operations in the Chattahoochee National Forest. There are four days of military mountaineering training, four days of technique training, 10 days of student-led patrols and one administrative day when students are counseled on their performance. Those who pass will move on to the third and final phase of Ranger School in the swamps of Florida beginning Aug. 1.

The effort at the legendary school was launched this year as the Army grapples with which combat jobs it should open to women in the future. The service included women in the school following a January 2013 directive by senior Defense Department officials to research the roles women could undertake and make recommendations later this year.

Any woman who passes the course will make history and be allowed to wear the Army’s prestigious Ranger Tab, a decoration that is admired across the military. However, they will not be allowed to join the elite 75th Ranger Regiment, which conducts Special Operations missions.

The effort has been closely scrutinized inside and outside the Army. The remaining three women are the last 0f 19 who attempted the Ranger Course beginning April 20. Sixteen of them passed an initial physical fitness test and eight made it through the initial Ranger Assessment Phase, commonly known as “RAP Week.” But all eight had fallen short twice, and only the three still in training now were allowed to attempt Ranger School a third time. Historically, about 75 percent of students who make it through RAP Week go on to graduate the course.

Sources familiar with the assessment told The Washington Post last month that some of the female students were shocked and frustrated when they learned they did not pass the Darby Phase. Most, if not all, of those women were dropped based on how they did while leading foot patrols through the wooded hills of Fort Benning. That raised questions with some critics about whether the women were being graded by the all-male cadre of Ranger instructors.

Army officials have defended the grading process, and attributed the previous failure of women to get through the Darby Phase to inexperience with patrolling.