In 1863 this area was a shebeen, or outlaw headquarters, where murder and robbery of travelers were commonplace. The valley lay on the main and original Nez Perce Trail leading into Montana through Elk City. Homesteaders later moved into the fertile valley, and by 1900 two towns were growing there: Culdesac at the end of the railroad terminal and Mellen at the east end of the valley. Citizens of both towns applied for a post office under the single name Cul-de-sac, and although the post office was granted, the department suggested the name Magnolia. That remained in use until a citizens petition led to the post office being renamed Culdesac. In 1903 the towns consolidated under the name Culdesac. With a population of 400, the town grew rapidly and boasted the businesses of a larger town, but a number of fires over the years burned entire town blocks and severely hindered growth. Even so, a school, businesses, and homes were rebuilt, and farming became the chief industry.