CONGRATS SP&S FAN FOR FIRST TO FIND
If you are following the Yellowstone Trail from East to West... From Grandview Pavement, turn North (Right) on Sunnyside Mabton Hwy (241). Mabton in it's Heyday was a booming railroad town. This Cache is in the Port of Sunnyside Area, among the Cornfields... hills to the North and the hills to the South.
History of the Yellowstone Trail......
In 1912, a group of small town businessmen in South Dakota undertook an ambitious project to create a useful automobile route, across America. At a time when roads weren't marked, there were few maps and slippery mud the usual road surface. By 1914, towns would create trail markers along the trail. They painted anything: posts, telgraph poles, rocks, sandstone hoo-doos; they made metal signs with the Trail name and some with only a black arrow on yellow background; sometimes with just a yellow "R" or "L" to guide the traveler to the correct direction. Keep your eyes open and you may spot an undiscovered sign.
The Yellowstone Trail Asn. located a route, motivated road improvements, produced maps and folders to guide traveler, and promoted tourism.
Today, almost all of the route of the YT is on slower, less traveled roads. Some sections, especially in the West, have remained little changed and are a delight to visit. Until 1925, the YT traveled south from Spokane to Walla Walla then up through the Yakima Valley and on to Ellensburg. After 1925 the route changed to travel from Spokane west to Wenatchee.
The concrete that was poured nearly a century ago was something of a cutting-edge experiment in road construction technology. Bidding was competitive and contractors were proud enough of their work that they stamped their name and the pour date into the pavement at regular intervals.
Information Sources:
http://www.yellowstonetrail.org/