While North Cascades National Park is in a remote region for the most part, the prevailing westerly winds bring various pollutants into the park from the industrialized region around Puget Sound and the Fraser River Valley of British Columbia. These pollutants deposit onto plants and glaciers and are then carried by rainfall or ice melt and dispersed into rivers and lakes. The industrialized regions around Puget Sound and the Fraser River Valley have had a more noticeable negative impact on water and air quality than at Mount Rainier National Park well to the south due to the prevailing winds. Lakes at higher elevations show a higher level of acidity due to this phenomenon; the current and long-term impact on the ecosystem of the park has not yet been fully assessed.