Robert Sibley Volcanic Regional Preserve Professional Review and Guide
"What do the Robert Sibley Volcanic Regional Preserve and Mount Saint Helens have in common? The subduction process that caused the explosion here ten million years ago of a great volcanic center eventually moved northward to cause the activity and eruption of Washington’s Mount Saint Helens. The park trail guide available at the trailhead includes a self-guided tour of Round Top’s fascinating geological journey. Hiking among Monterey pines and on open grassy hills, you will see walls of the caldera left by the ancient blast, old river gravels, basalt lava flows, and varicolored “redbeds,” layers of oxidized iron explored worldwide for fossils. Remains have been found of mastodons, hipparions, camels, and prongbucks in the old quarries here. More recently, enthusiastic hikers have built a series of rock mazes in the quarries, complete with altars at their centers. Walking through these formations and admiring the offerings at the altars provide great entertainment. The park is pleasant for walking or jogging. Overall, the hike is easy but with many rising and falling slopes. Those wishing them can find steeper descents up to Round Top and out of the quarries. This eTrail also includes suggested nearby attractions, camping & lodging, restaurants, and local outdoor retailers."