Well, I've never been knows for my sanity, but I'm leaning hard towards doing the 600K. While the 24-hour ride sounded like fun, it's really just around a huge parking lot in a park, with about 150-feet of elevation per 1.5-mile loop. So, even if I only aimed for 300 miles, that's 30,000 feet of gain. Ouch! I would rather do the 600K. So, that's what I'm gonna do!

How bad can it be....