 A "water-grade" route for US 97 along the east bank of the Columbia River was envisioned in the 1940s and was constructed in sections as part of improvements to SR 151.These improvements included a new alignment for the highway during construction of the Rocky Reach Dam and a new bridge crossing at Chelan Falls.The $14.6 million alignment (equivalent to $ in dollars) following the river for between Chelan Falls and Azwell was opened in September 1985, completing the water-grade route along the Columbia River.