Ocean Remote Sensing Group within the Johns Hopkins University. Maps include: relief map, county map, false color satellite images (AVHRR), historical 1895 map. fermi.jhuapl.edu/states/or_0.html
According to the official government survey, the main trunk of the Oregon Trail stretches 1930 miles from Independence, Missouri, to Oregon City, Oregon. endoftheoregontrail.org/maplibrary/oregontrail.html