Issued on July 14, 1936, this violet 3-cent stamp marked the 100th anniversary of the establishment of the Oregon Territory. The Oregon Territory comprised the present states of Oregon, Washington, Idaho, and parts of Montana and Wyoming. Settlement of the region followed swiftly after the Lewis and Clark expedition of 1804, leading to official territorial status in 1836.
The stamp shows a map of the Territory, including a trace of the Oregon Trail. The map is flanked by a Native American scene on the left and a covered wagon train on the right.