Cathedral Rock Trail takes you up into the saddle of the famous rock formation.  There are many ways to get to this trail.  I chose to start from Littlehorse Trailhead.  This route requires you to take the following Trails:

1. From Little Horse TH head down S. Bell Rock Parkway.
2. Head Right on HT Trail until it runs into Templeton Trail.
3. Take Templeton till it runs into Baldwin Trail and head right again.
4. Cathedral Rock Trail will be on the left side.

Got it? Maybe just consult this map.