| Caverns were formed under the park and surrounding area by cooling lava from Mount Rainier. These caverns are presently being used for the storage of natural gas. | | • Cedar
• Douglas Fir
• Hemlock
• Alder
• Cherry
• Maple
• Oak
• Lupines
• Rhododendron
• Rose
• Berries
• Ferns
• Moss or Lichens
| The park features euonymus occidentalis, Pacific yew, wet prairie and views of Mount St. Helens, Mount Rainier and Mount Adams.
|