Hi Scott,
Was just thinking about you so I came over to the forum and saw that you have posted this earlier this month. I am not familiar with the current course for the Leadville Marathon, the last time I ran it, the course was a lop of Turquoise Lake. I think Jerry was there last year or the year before, I will ping him about it.
He and I could give you lots of data about the 100 miler as we have both been there..you might want to think about that one. My daughter is going to give it a shot this year. She just finished the Rocky Raccoon 100 last month and now want to take on something with more challenge (not that RR is not a challenge, but 10000ft and hope pass...). Her problem will be coming from sea level. She is no longer a mountain lady. Last year at the Wild West Relay, she suffered big time on Rabit Ears Pass.
I do know that mosquito pass is no picnic but I did not see a course map on the website. The topo of the course does not look like there is anything super steep. Check out this link:
http://maps.google.com/maps?q=http://tr ... ues=180309 Not sure if this is the course but it is reported to be.
Bob