- Silver Lake is a small, deep alpine lake in northwestern Washington, United States, within the northeastern portion of North Cascades National Park, near the border with the Canadian province of British Columbia. It is located within a high-altitude cirque and is primarily fed by Silver Glacier on the slopes of Mount Spickard, and drains through Silver Creek, ultimately into Ross Lake. It was first documented in 1905 and declared a Research Natural Area in 1974.