You are looking for a camouflaged micro. The cache is only a short walk from the trailhead, which can get full especially on weekends. It is also just a little ways off the trail. My GPS was bouncing around a bit, so you might need to expand your search area a bit, shouldn't be more than 30 feet from GZ. The trail can be pretty busy, so watch out for muggles.
There is a nearby, steep slope down to the reservoir. You DO NOT need to get on this slope to find the cache, but if you are caching with your kids keep and eye on them.
The best time to look for this cache would be June to early October due to winter weather conditions. You could find it with snow on the ground, but the terrain rating would be quite a bit higher. Access in the winter would be by snowmobile.
If you find this cache you might also take the time to look for the Mandall Creek Gateway to the Wilderness cache (GC61H29) at N40 02.831 W 107 05.049. It has been in place since 2015 and as of July 21, 2017 still hadn't been found and not because it is real difficult. It is just a 3/4 mile hike in from the trailhead for trail 1121 which is near the turnoff to the Bear Creek campground. It is similar to this cache.