Denny Mountain is a prominent summit in Washington’s Alpine Lakes Wilderness near Snoqualmie Pass, rising above the transportation corridor now followed by Interstate 90 and beside the Alpental ski area. It was named for Arthur A. Denny of the Denny Party, who oversaw construction of the Snoqualmie Pass Road, the route that later became I-90 along the mountain’s southern base. That connection links the peak to the early development of one of the main crossings of the Cascades. The mountain also reflects the west side’s marine climate, with heavy Pacific-driven precipitation, deep wet snowfall, significant avalanche danger, and clearer summer weather.