Further southeast along the river , SR 504 passes the privately owned Eco Park resort , a youth camp , and a heliport near the Hoffstadt Bluffs Viewpoint . The highway then crosses over Hoffstadt Creek on a steel truss bridge that sits above the valley floor ; it is the longest of 13 bridges on SR 504 . The bridge also marks the western extent of the " blast zone , " where trees were felled during the 1980 eruption of Mount St. Helens , located away . The area has large forests of young fir , pine , and cottonwood trees planted by Weyerhaeuser in the 1980s as part of a regeneration and restoration project . The company also operates the Charles W. Bingham Forest Learning Center , a museum that overlooks the North Fork Toutle River and also includes a rest area
1980 eruption
1980 eruption of Mount St. Helens
Washington State Route 504