From the man that brought you "For wood into wood" and "Bite the bullet" comes a series of two bush micros. You are looking for a very well hidden yet extremely poorly camouflaged bison tube. The cache gaurdian is holding the cache. Be gentle with him and he'll tell you the secret soon enough.
Again, what you're looking for is a lot (LOT) bigger than a micro, so look in the usual hiding spots. Bring your own pen. Beware of dad jokes.