Ruby Creek is a tributary of the Skagit River located in the North Cascades of Northwestern Washington. The river's watershed drains the southern Washington portion of the Hozameen Range, and the western section of the North Cascades Scenic Corridor. The creek was named by three prospectors, John Sutter, George Sanger, and John Rowley, in 1872. Sutter believed he found a ruby in the creek, leading to the name, however the stone was actually a misidentified garnet. Ruby Creek had an original length of approximately 11 kilometers, before the lower 6 kilometers were inundated by Ross Lake, reducing it to its current length of 5 kilometers.