Mount St. Helens National Volcanic Monument is within Gifford Pinchot National Forest. It is most conveniently reached from the west side, as shown on the map below. From Interstate 5, take exit 68 and proceed east on State Highway 504. Five different visitor centers can be found along highway 504.
Mount St. Helens National Monument and Gifford Pinchot National Forest may also be accessed from the east side, via forest service road #99, or from the south, via State Highway 503 and the town of Cougar.
Within Gifford Pinchot National Forest and Mount St. Helens National Volcanic Monument, the only connection between the major highways is via forest service roads. A forest service map, in addition to a state highway map, is highly recommended for visitors who plan to stray from Highway 504.