I've been riding with the Ohio randonneurs, but couldn't make their 600k, so I'm doing the St. Louis 600k. They don't have on-line registration so I have no idea how many people will be riding. Looks like it's going to be rough, with temps in the mid to upper 90's and high humidity. Hopefully I can find a reasonably friendly stranger to ride with, because riding all day alone in these conditions is probably not a good idea. I hope to ride just fast enough to get 5-6 hours of sleep in Vienna.