In 1843, one of the first things the new governor of the Oregon Territory did was try to find a better Oregon Trail.
The governor, George Abernathy, wanted to quickly populate the area with Americans to keep the British out, so he ordered a group of explorers to find a better way through the treacherous Cascade Mountains.
The first group searched the entire length of the west side of the Cascades but couldn’t find an opening. In 1846, Jesse Applegate led the South Road Expedition in another attempt. They rode through Indian Country to the Rogue River where they turned east. They made their way past Tulelake, then found a trail through Modoc County that led them over Fandango Pass into Surprise Valley. While there, they picked up tracks leading to High Rock Canyon, which opened into the Great Basin.
After the discovery, Applegate invited approaching emigrants to take the new South Road. High Rock Canyon, 40 miles south of Surprise Valley in Nevada, is now a 46,000-acre Wilderness Area, preserving the axle-grease and letters carved into the rocks by those early Oregonians who left their names while passing through.
Source: Davis, Charles G. "South Road Expedition, a Voyage of Discovery." Oregon-California Trails, 1999, pp. 287-91.