Roughly 50km north-east of the city of Yuma, Arizona, is the huge (3,387 square km) US Army Yuma Proving Ground. It is home to a 55-mile (89km) overland artillery range, the longest in the nation.
Almost all ground-based weapon systems are tested at YPG, from small arms to the largest of heavy artillery. While no atomic testing took place there, many inert shells were fired from the mighty M65 atomic cannon during its test phase. Also, the high-altitude research project (Harp) gun was tested here. Harp was a joint US and Canadian project using a special gun made of two 16in gun tubes from a US Navy battleship, joined to create a barrel more than 120ft long.
If the name Yuma seems familiar to CMV readers, it may be due to an article last year on the Overland Train. In addition to the Overland Train, YPG has an open-air park with numerous other items tested over the years.