Chief Umtuch (sometimes spelled Chief Umtux, or other variations on the name) is the of an 'indian' chief who lived in the area of Battle Ground, Washington, when Washington was a de facto British territory.
There had been some minor skirmish or trife between the Indian tribe that lived in the area, and the military presence at The Hudson's Bay Company Fort Vancouver. Wanting to smooth things over, Chief Umtuch and the commandment of Fort Vancouver got together to talk things over. They quickly worked over their differences, and exchanged coats and fired off some guns to celebrate their new found understanding.
As Chief Umtuch was riding back to Battle Ground to tell his tribesman the good news, a group of his warriors, who had heard the gun fire, and saw a man riding up in a British Army coat, thought that their chief had been assassinated, and that an army was coming to invade their territory. So they shot and killed the man who they thought was a British officer, but was actually their own chief. He died of his wounds.
It was this accidental shooting that was the 'battle' that gave Battle Ground its name.