I chose the Indian Creek Fifties, which is part of the Human Potential Running Series here in Colorado, mostly because the timing worked out well with my schedule. But, upon reading some race reports from previous participants, I concluded that it would also present a fair challenge in terms of not only distance, but in net elevation gain as well (just under 12,000' of net climbing).
Enough talk. Time to get training!
P.S. - Had a blast running the Colfax Marathon Relay with my dear Red Shirt Racing Team last weekend! Love sharing miles with those guys and gals. :)