Jack Mountain is a high, rugged North Cascades peak in Washington, notable as the state’s seventeenth highest mountain and one of only ten non-volcanic summits there above 9,000 feet. Rising dramatically above Ross Lake, it is marked by severe glaciation, especially Nohokomeen Glacier on its upper north slopes, along with several other glaciers and steep drainages. Surveyor Henry Custer first described and named the mountain in 1859 for prospector Jack Rowley, and topographer E.C. Barnard made the first recorded ascent in 1904. Its difficult climbing, long approaches, and complex rocks reflect both its formidable terrain and the complicated geologic history of the North Cascades.