found: Encyc. Amer., 1990(Oregon Territory, est. 1848)
found: The Oregon book information A to Z, 1998:p. 416 (Oregon Territory included what is now Oregon, Washington, Idaho, and western Montana)
found: The encyc. of Oregon, 1999:p. 60 (The new Territory of Oregon embraced all of the original Oregon Country between the 42nd and 49th parallels from the Rockies to the Pacific)
found: Empire of the Columbia, 1957:p. 287 (President Polk signed the bill creating the Oregon Territory on Aug. 14, 1848. In Mar. 1849 the territorial government was declared to be in operation)
notfound: Wikipedia WWW site, June 12, 2008 (In 1853, the portion of the Oregon Territory north of the lower Columbia River and north of the 46th parallel east of the river was organized into the Washington Territory. In 1859, "the territory entered the Union as the U.S. state of Oregon within its current boundaries. The remaining eastern portion of the territory (the portions in present-day southern Idaho and western Wyoming) was added to the Washington Territory");Dict. of Oregon history, 1989: p. 206 (Provisional government. On May 2, 1843, a group of citizens gathered in Champoeg and voted to form a civil government. Later, the Organic laws were formulated: "We the people of Oregon Territory, for the purpose of mutual protection ... agree to adopt the following laws and regulations until such time as the United States of America extend their jurisdiction over us."; "Arrival of Oregon's first Territorial governor, March 2, 1849, terminated the official life of the Provisional Government.")