I love this place, and there was room for another geocach, so here it is.
You are looking for a micro container with a log, but the container size really isn't important here. The cache itself is about a regular. If that doesn't make much sense now maybe it will when you find it. It's in the great outdoors, and anything in the wide open spaces that isn't really huge looks small.
The best place to park is just south of the bridge on Plainview Road. At N39 52.688 W105 16.184. Unless it's spring, or Coal Creek is unusually high, take the trail south of coal creek at the above location. Normally you can cross over Coal Creek near the dam N39 52.646 W105 16.418 without getting your feet wet. If Coal creek is high (Springtime) you will have to take the slightly longer, more difficult route by following the path just north of the bridge. I would not recommend parking on Coal Creek Canyon Road.
There isn't really room for a pen. We prefer geopens, but really any kind will work nicely.
This is not intended to be a rock pile search.
You can leave your ladder home for this one too.
Your dog will love helping you find this one.
No cats allowed! 
Sorry Mondo, your jeep probably won't get you here. 
There are three other caches on the hill. Wile you are here you should also check out GCHAQZ - Geo-Gear Cache. You can see it's location from here.