Powder Mountain Utah...What I liked about this place is they had everything, BC, resort runs...and a shuttle to pick you up down the road and bring you back top. And it wont take all your money either say compared to Colorado..
My suggestion is wherever it is. If u want people from all over the airport has to be convenient such as SLC...and it has to be an airport that services many destinations and arrivals to accomodate everyone.
They also have HUGE houses they rent...that is where u will have to bear down and crunch the numbers so people can decide if they can afford to go for many will have to have an idea of the real cost.
Myself for every meet Ive been on its cost less than a grand. Anything over I spent on gifts and stuff. Your gonna have alot of planning ahead of you.
Honestly I would keep the meet to a minimum. Because the liability falls upon whoever sets it up..ie:housing contracts that sort of thing. VS will not support or "cover" in the event of damage or problems. Typical internet site..they want their cake(we love meets adm used to say) yet....they wont back u up if there is a problem..
50 people increases the risk chance compared to say 20 or less...Just trying to give u a little heads up is all dont take offence please...
In these cases...the MORE may not be the merrier....