Mountain Biking Highlight
Water, wind, and calcite erosion in peri-volcanic sandstone formation.
Slightly acidic rain water seeps into the sandstone during winter rains and dissolves some of the calcite. Warm and dry days cause the moisture to pull the dissolved calcium back out of the rock, causing holes and caves to form.
Watch for peregrine falcon and other birds of prey nesting high up in the Castle Rock caves.
The upper trails are closed Feb-July to avoid disturbing the nesting birds.Great area for hiking and mountain biking:
June 16, 2016
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