Weather seems to be totally unpredictable in Wyoming. Chances are it will be warm and dry in September, but you could also have 2 feet of snow on the ground. Or like last year when we were in a nearby unit, last week of September, and it rained for 3 or 4 days straight. Made it really tough getting around with all the muddy roads. If you can, try to keep your dates flexible so if the weather is bad you can wait and go when it gets better. I haven't hunted 73 but I would expect a lot of pressure especially the first week, because that unit has a huge number of tags.