As a former high school wrestler, youth coach, and parent of two boys invovled in wrestling, I have observed from these three perspectives what I feel is important to build a powerhouse. I believe that administrators at a school first have to have the idea of that they want to spend money and get behind the program. The next thing is a highly motivated coach. One could argue that a motivated coach could get administration on his side with vision and increasing success over time, so maybe administration and the coach go hand in hand. In my opinion, these are the cornerstones to building a powerhouse, but I think most of what MattM replyed comes after these two are in place.
I would be naive to think recruiting doesn't happen, but I'm not sure if a coach really needs to much if a successful program is already built, "...if you build it, they will come."
I do not want to muddy the waters with the discussion of money, I understand that a coach needs to make a living just like anyone else. That being said, money is a huge part of the building. Camps, club membership, gear, venues, travel, and a motivated coach all cost money. If parents don't or can't spend the money for their child to get the training he or she needs or don't or can't spend the money to travel to large prestigous tourneys that give invaluable experience, the child has a larger hill to overcome at state tourney time for example.