The land area on which the Fort Drum military reservation is currently located has been used as a military training site since 1907.

In 1908, Brigadier General Frederick Dent Grant, son of General Ulysses S. Grant was sent here with 2,000 regulars and 8,000 militiamen. He found Pine Plains to be an ideal place to train troops. The following year, money was allocated to purchase the land, and summer training continued here through the years.

The camp's first introduction to the national spotlight came in 1935 when the largest peacetime maneuvers were held on Pine Plains and surrounding farmlands. Thirty-six thousand, five hundred Soldiers came from throughout the Northeast to take part in the exercise. Some Soldiers traveled by trains that arrived in town every 15 minutes, coming from as far away as Buffalo and New York City. For 36 hours, young men from offices, factories and farms marched, attacked and defended in tactical exercises on the 100 miles the Army had leased for its war games. The maneuvers were judged to be most successful and the War Department purchased another 9,000 acres of land. With the outbreak of World War II, the area known as Pine Camp was selected for a major expansion, and an additional 75,000 acres of land was purchased. Eight hundred buildings were constructed: 240 barracks, 84 mess halls, 86 storehouses, 58 warehouses, 27 officers' quarters, 22 headquarters buildings, and 99 recreational buildings as well as guardhouses and a hospital.

Construction workers paid the price, as the winter of 1941-42 was one of the coldest in North Country history. The three divisions to train at Pine Camp were General George S. Patton's 4th Armored Division (General Creighton Abrams was a battalion commander here at the time), the 45th Infantry Division and the 5th Armored Division. The post also served as a prisoner of war camp. Pine Camp became Camp Drum in 1951, named after Lt. Gen. Hugh A. Drum, who commanded the First Army during World War II. During and after the Korean Conflict, a number of units were stationed and trained here to take advantage of the terrain and climate.

The post was designated Fort Drum in 1974 and a permanent garrison was assigned. In April 1980, B Company, 76th Engineer Battalion (Combat Heavy) was reassigned here from Fort Meade, Md. The rest of the battalion, less Company D, followed it three years later.

In January 1984, the Department of the Army announced it was studying selected Army posts to house a new light infantry division. On September 11, 1984, the announcement was made that Fort Drum would be the new home of the 10th Light Infantry Division.

The first division troops arrived at Fort Drum on December 3, 1984, and the unit was officially activated on February 13, 1985. The name was changed to the 10th Mountain Division (Light Infantry) at that time. The division reached full strength in 1989. Between 1986 and 1992, 130 new buildings, 35 miles of roads, and 4,272 sets of Family housing units were built on post.

Today, the 10th Mountain Division (LI) is expanding once again under Army Transformation. A third brigade was added to the division and Fort Drum in 2004, and a fourth brigade to 10th Mountain Division is also housed at Fort Polk, La. By the end of fiscal year 2005, Fort Drum employed more than 15,000 Soldiers and over 3,000 civilians.

Elements of the 10th Mountain Division (LI) have deployed in every major operation the Army has participated in since the early 1990s. These include, but are not limited to the following: operations Desert Shield/Storm 1990-1991; Hurricane Andrew Relief 1992; Operation Restore Hope in Somalia 1992-1994; Operation Continue Hope, 1993-1994; Operation Uphold Democracy in Haiti 1994-1995; Operation Joint Guard in Bosnia 1997; Task Force Eagle in Bosnia and Herzegovina 1998-2000; Operation Enduring Freedom in Uzbekistan and Afghanistan 2001-2002; Operation Noble Eagle in the United States after Sept. 11, 2001; Operation Enduring Freedom 2001; Operation Enduring Freedom IV/Operation Iraqi Freedom 2003-2004.

The division continues to support operations in Afghanistan and Iraq and continues to play an important role in the Global War on Terrorism.