The rugged Crags are granite bodies, or plutons, from the Jurassic time.
Like Yosemite's Half Dome, Castle Dome cooled underground.
We headed about 90 miles into California from Oregon for a training hike last weekend. As the challenge of an Alps trek next month nears, Castle Crags State Park gave us a chance to test our lungs and legs in the Shasta National Forest.
The seven-mile walk took us up about 2,500 feet to reach the granite formations more than 170 million years old. A collision of an oceanic plate with North America created the Crags.
The Crags Trail is all uphill and steep scrambling over rocks made the last mile quite difficult.
A food and beer fueling stop on the way home capped a tough, but rewarding day.
Crags Trail gets rockier and steeper when it emerges from the forest.
There are about 28 miles of trails in the Castle Crags Wilderness. The Pacific Crest Trail is part of the trail system.
The trail offers hikers several views of 14,000-feet-plus Mount Shasta.