Harvest of Souls War
From AmtWiki
The Harvest of Souls War started with an invasion of The Duchy of Pegasus Valley's park by the Iron Mountains in 1996 and became a full camping event in the following years. The Harvest of Souls War takes place in New Mexico over the Labor Day weekend each year. Recent years have seen more role-play and non-fighting events such as the Viking Games and Pathfinder Games with the weekend ending in a large themed battlegame.
The event title is often shortened to "Harvest War".