the town of Toutle, controlled by a roadblock and an existing turnaround loop installed by Weyerhaeuser. Access to Kid Valley was restored by early September using a temporary Bailey bridge over the Toutle River. The highway was extended to the debris and sediment dam and Weyerhaeuser's Camp Baker site in 1987 at a cost of $11 million (equivalent to $ in dollars). In 1982, the federal government designated the area around the volcano as the Mount St. Helens National Volcanic Monument and the state government designated SR 504 as the Spirit Lake Memorial Highway to honor the victims of the eruption. A visitor center was also opened at Silver Lake in 1987 to serve the growing number of tourists to the area, but the highway would remain closed beyond the sediment dam. Preliminary plans for a replacement for the highway to serve the north side of Mount St. Helens were approved by the state government in 1986. The highway would include of new road built at a higher elevation between Kid Valley and the newly formed Coldwater Lake, crossing over various creeks with ten major bridges. The project's $118 million cost (equivalent to $ in dollars) was paid from emergency funds from the Federal Highway Administration. Construction of the new highway and its scenic viewpoints began in 1988 and the first section to the Coldwater Ridge visitor center was completed on October 16, 1992. The expected influx of tourists and their potential impact on the recovering habitat around the volcano alarmed scientists looking to preserve areas for sensitive research. After finding that elk herds were leaving areas with improved highway access, the Forest Service established restricted zones within the national monument that prohibited off-trail hiking, pets, fires, and camping. Two additional visitor centers, Weyerhaeuser's Forest Learning Center and the former Hoffstadt Bluffs Visitor Center, opened in 1995 at milepost 33 and 1996 at milepost 27, respectively. In May 1997, SR 504 was extended to its current terminus at the newly opened Johnston Ridge Observatory, named for volcanologist David A. Johnston. Construction of the extension included underground blasting to compact soil and provide one of the highway's bridges with a stable foundation. It replaced an original plan to build a forest road that would be used by shuttle buses between Coldwater Ridge and the Johnston Ridge facility. 21st century A long-proposed extension of SR 504 to the eastern side of the