i know that in skinning you need finkle's skinner to get to the skill lvl 305-310 needed to skin core hounds in MC for core leather/hides. in fishing there are some things only obtainable by 400+ skill lvls (using fishing accessories that boost your skill lvl. it would stand to reason there must be some mines that are only accessible at the 305-310 range obtainable from glove enchants, etc. i hope to find them out as well... as i am reaching the higher lvls.. 272 atm