segment of the Pacific Coast Ranges (see Pacific mountain system), southeastern Alaska, U.S. The mountains are named for Ferdinand P. Wrangel (Wrangel, Ferdinand Petrovich), a 19th-century Russian explorer. Roughly 60 miles (100 km) wide, they extend for about 100 miles (160 km), from the Copper River to the St. Elias Mountains (Saint Elias Mountains) near the border with Yukon Territory, Canada. Many peaks exceed 10,000 feet (3,000 metres), including Mount Blackburn (16,390 feet 【4,996 metres】), the highest point in the range, and Mount Sanford (16,237 feet 【4,949 metres】). Snowfields drain into glaciers as long as 45 miles (70 km). Most of the summits are extinct volcanoes; Mount Wrangell (14,163 feet 【4,317 metres】) was the last to approach the dormant stage. Rich copper deposits were discovered north of McCarthy in the early 20th century, and some gold, copper, and zinc mining continues. The mountains form a major part of the Wrangell–Saint Elias National Park and Preserve, which, with Glacier Bay National Park and Preserve (Alaska, U.S.), Kluane National Park and Reserve (Yukon Territory, Canada), and Tatshenshini-Alsek National Park (British Columbia, Canada), forms a World Heritage site.