Taken from the official 10th mountain website
To meet the Armys requirements to train large numbers of
replacements the 10th was reactivated as a training division on
July 1, 1948, at Fort Riley, Kansas. It didnt retain its wartime
designation as a Mountain Division and as result lost its
"Mountain" tab. The Division had the mission of processing and
training new soldiers for service with other Army units. The
outbreak of the Korean Conflict in June 1950, enlarged this
mission. A total of 123,000 men completed basic training with the
10th during the period 1948-1953.
The Division was officially reactivated on February 13, 1985, at
Fort Drum, New York as the 10th Mountain Division (Light Infantry).
The division commander after reactivation was Brigadier General
William S. Carpenter. The 10th was the first division of any kind
formed by the Army since 1975 and the first based in the Northeast
US since World War II. The 10th Mountain Division (LI) was
designed to meet a wide range of worldwide infantry-intensive
contingency missions. Equipment design was oriented toward reduced
size and weight for reasons of both strategic and tactical
mobility.
Website is here http://www.drum.army.mil/history/divisionhistory.htm
It operates much the same way as the 25th infantry division
They are currently the only 3 regular US army divisions that are
still light infantry.The rest are Mechanized Infantry.The 82nd and
101st are the 2 Airborne left.
Edit:the 7th infantry is also light i think....i'm guessing since
they're website is not really good and they only have 1 armoured
bde instead of something like 3 for the mechanized troops.