It followed the Oregon Trail… so the Oregon Trail came first?
Actually, as an emigrant road, the Oregon Trail is exactly as old as the California Trail. A party of about a hundred families was headed for California in 1841, but they split at Fort Hall when half of them decided to settle in Oregon, instead. Before gold was discovered in California, most settlers were Oregon bound, so the entire length of the trail is generally called the Oregon Trail, not just the leg that led to Oregon. On the other hand, the route across the plains, which followed the Platte River for most of its length, was used by thousands of Mormons headed for Utah as well as overlanders headed for Oregon and California, so it’s sometimes called “the Great Platte River Road” to avoid any confusion about who was following it.
