Yellowstone Trip Dates

I'm looking at dates for our Yellowstone trip next year. I've talked with the council out there. This camp is at 6000 feet elevation so June will be colder at night. June is more wet. July is hot and dry. I need to understand what weeks you CAN NOT go. We are planning on this as our primary option for Summer Camp next year. We will also have a smaller contingent of scouts and crossovers (who do not want to go to Yellowstone) going to Maumee next year. Please take into consideration that we will be leaving mid week of the week prior and returning mid week of the following of whichever week we do go. You can select multiple options but can only vote once. Figure $500 a scout to just do the week program at camp plus travel expenses getting there and back.