Columbia Mountains are a block of mountains 608 km long and 256 km wide that dominate the landscape of southeastern BC. The Monashee, Selkirk and Purcell mountains form parallel lines extending north-south from the US to the Rocky Mountain Trench. Minerals in the Purcells, between the valley of Kootenay Lake and the trench, have been exploited since the 1890s, notably silver-bearing lead-zinc ore from Cominco Ltd's huge Sullivan Mine in Kimberley. Alpine areas such as the Bugaboos are increasingly popular for skiing and hiking. To the NW, between the Quesnel-Shuswap Highlands and the trench, are the Cariboo Mountains. They include Bowron Lk Prov Pk and most of Wells Gray Prov Pk, both noted for outstanding scenery and recreation.