North Cascades National Park has nearly of vertical relief, with the park's highest point atop Goode Mountain, and the western valleys situated at only around above mean sea level, the park has a highly varied ecosystem, including eight life zones. Erosion from water and glacial ice have created some of the steepest mountain ranges in the contiguous US, rising between above their bases. The park is home to over 300 glaciers as well as 300 lakes, and contains the headwaters for some streams that flow into the Skagit River, as well as the Stehekin and Nooksack Rivers. The ruggedness of the terrain was an obstacle to human encroachment and consequently, the park is almost entirely wilderness, though it is only from Seattle-Tacoma International Airport.