Start in the parking lot of Rock Park. Hike up the trail leading south out of the trail until it forks. The fastest way from here is to take the right fork as it switchbacks it's way up the western end of the mountain. This trail can be fairly steep in places although the city of Castle Rock does a fairly good job of maintaining it. Continue on this trail until it arrives at the base of the cliffs of the summit block.
Walk around the summit block to the northern side. If you walk around the western edge you can walk under the overhang and get a better feel for the scale of Castle Rock. It's pretty big. The ascent route goes up an obvious break in the sheer walls on the north side. I will try to describe the best way up, although the best advice would be to pick what seems the easiest.
There are two breaks in the north face, which are separated by a vertical wall with a huge boulder balanced on top of it. The easiest way up is through the left (east) break. Hike up to under the tree and you should see a sort of stair system that leads between the boulders and over a series of ledges. Near the top you will enter a sort of ravine where you can walk up to the summit plateau.
For a little more exposure try the western (right) break. Hike up to the first small cliffband and find a series of small steps leading up over it. Traverse east on top of this cliff band towards the large boulder and either climb over it or under it. This traverse requires one exposed move where you have to step onto a large but hidden ledge in another smoot rock. Once on top of the boulder the summit is a quick walk up through the aforementioned ravine. For an even greater challenge climb up the prominent directly above you before you reach the boulder.
These routes are great to do with kids or beginner climbers since there are several places for them to explore including various chimneys, "caves", arches and even a tunnel deep in the rock.
Sun protection about covers it.
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