A good overview of the Leadville marathon course from Brandon Fuller.  From his account this is the typical Jeep road course, meaning a torn up steep course of big rocks and steep grades, much like Imogene.  I know first hand how difficult and frustrating it can be to get a good climbing (or descending) cadence on a rocky, bumpy road, compared to a smooth trail.  

A good overview of the Leadville marathon course from Brandon Fuller.  From his account this is the typical Jeep road course, meaning a torn up steep course of big rocks and steep grades, much like Imogene.  I know first hand how difficult and frustrating it can be to get a good climbing (or descending) cadence on a rocky, bumpy road, compared to a smooth trail.