self-propelled howitzer

What an excellent image.
The gun is an M-7, (Priest) a 105mm howitzer mounted on a medium tank chassis, weighing 30 tons. It was used by the 300th Armored Field Artillery Battalion of the Wyoming National Guard.

The 300th Armored Field Artillery Battalion entered active duty on August 19, 1950, to fight in the Korean War. The battalion was composed of Headquarters Battery, Sheridan; A Battery, Thermopolis; B Battery, Cody; C Battery, Worland; and Service Battery, Lovell.

It became the most decorated Wyoming National Guard unit of any war, receiving the First Presidential Unit Citation for the Battle of Soyang, the Second Presidential Unit Citation for the Battle of Kumsong, the First Republic of Korea Presidential Unit Citation for the Battle of Soyang, the Second Republic of Korea Presidential Unit Citation for the Battle of Kumsong and a Meritorious Unit Commendation Korea 1952-1953.

Eleven soldiers died in battle, and 173 suffered wounds. A cease-fire began on July 27, 1953.

The battalions 18 howitzers, mounted on a tank chassis for close support of the infantry, fired 514,036 105mm cannon rounds in 805 days of combat.