Before hunting the cache, we suggest reading the signs posted on the outside of the facilities. Then wander over to peek in the school, and maybe even out back to the livery. From there, you can head to the cache - across the pet area and into the corner. Its a pretty routine hiding spot - no creativity involved. We just wanted to point out the best rest area we've ever come across. After a long day of caching along 395, you'll be glad to know this is here.
Cache container is now a small pill bottle. Room for very little trade items. I haven't been up here when there's snow on the ground, but since the ground is level and cache is inside the fence, I expect that it will be accessible as long as you don't mind trudging through the snow.
It probably doesn't need to be said, but just in case: treat the grounds lightly so that it may be enjoyed for years to come, and replace the cache as you found it. Muggles come in more than one size and shape around here.