CARLISLE, Pa. (AP) — Three Native American children named Little Plume, Horse and Little Chief died about 135 years ago while attending a government-run school in Pennsylvania.

On Monday, a team of experts made final preparations to exhume their bodies and take them home.

The process was expected to begin early Tuesday at the prim post cemetery on the grounds of the Carlisle Barracks, which today houses the U.S. Army War College.

Little Plume, Horse and Little Chief, also known as Hayes Vanderbilt Friday, Horace Washington and Dickens Nor, died in Carlisle in 1882-83 at the ages of 10, 14 and 15.

Seventeen members of the Northern Arapaho tribe, which in January 2016 formally requested the bodies be returned, arrived in Carlisle on Sunday to take part in what is expected to be a weeklong process. Their delegation includes tribal elders and young people.

The tribe had "certain requests they shared with us" and those will be carried out before and after the disinterments, said Art Smith, chief of Army National Military Cemeteries.

"Our goal is to interact with the tribes, treat the families with dignity and respect, in the most honorable way possible," Smith said.

The federal government is paying the estimated $500,000 cost to dig up, process and return the three to Fremont County, Wyoming, which encompasses most of the vast Wind River Reservation.

Experts will exhume the bodies by shovel and trowel — no machinery will be involved — after which the soil will be sifted to separate any human remains as well as buttons, jewelry, clothing, coffin material and other objects related to the three.

All of it, including the 1920s-era coffins, will be handed over to the families. The 240-pound (109-kilogram) stone grave markers are considered government property, so they will be analyzed, archived and disposed of properly.

Forensic anthropologist Elizabeth DiGangi will check the bones to see if they are consistent with the ages and sex of the three children. DNA tests are not planned.

"Every single skeleton I look at is the remains of a human being, and that's a human being who was loved by somebody else," DiGangi told reporters during a preview of the project organized by the Army.

A tent has been designated for ceremonial uses by Northern Arapaho tribe members, and another will be the scene of the handover of the remains for transportation to Wyoming.

The Carlisle Sentinel reported last month that records assembled by Dickinson College show all three arrived at the school on March 11, 1881, and all had both parents listed as living.

School ID cards offer scant biographical detail. Little Plume's father was a butcher named Bill Friday. In the space for Horse's home address, it said: "Washington (chief of police)." Little Chief's father was Sharp Nose, referred to on the ID card as "2nd chief."

The government-run Carlisle Indian Industrial School, founded by an Army officer, took drastic steps to separate Native American students from their culture, including cutting their braids, dressing them in military-style uniforms and punishing them for speaking their native languages. They were forced to adopt European names.

More than 10,000 Native American children were taught there and endured harsh conditions that sometimes led to death from such diseases as tuberculosis.

Little Plume, Horse and Little Chief likely died of some sort of infectious disease, said the project's chief archaeologist, Sonny Trimble.

They are among 181 Native Americans buried in the cemetery. They were first buried in a different cemetery nearby and were moved in 1927 to the current location.

Their graves are laid out with military precision, each marked by a marble gravestone customary in military cemeteries. Every grave has been freshly decorated.

The Army is reaching out to all of the nearly 50 tribes whose children attended Carlisle Indian Industrial School, and officials expect more exhumations and returns to eventually follow.