May 1 is a perfect start date, but I'm biased: I plan to start May 1. For anyone in shape - especially a marathon/ultra-runner - an avg of 14.43 mpd shouldn't be much of a challenge. That puts your end date at September 30. If your marathon times are consistently under 4h 45min this should be relatively easy, provided you do have some experience hiking, and that you're not planning many nero's and zero's. If you don't have any long-distance experience, if you haven't hiked through mountainous terrain, if you're carrying an inordinately heavy load, or otherwise burdening yourself in some way, the challenge could be greater. I transitioned from long-distance running and biking with years of racing/touring/commuting miles back in 2013, and although I wasn't able to hit 20+ with as much ease as I anticipated (far from it as I started SOBO), the endurance background was a huge asset. I turned 50 last year, and I have been hiking relatively big miles every year since 2013. For reference my times nowadays: 3h 37m marathon, 39m 10k, 29 mpd avg on last LASH from Springer over 862 miles. I'll be trying to hit just over 30mpd this year on my thru. Keep hiking and you should have no problem, I imagine. BTW Pronghorn antelope... the fastest land animal on the continent? Just goes to show you that college kids aren't always that smart. Not much meat on those things anyway, can't imagine they were ever the target of persistent hunting - which isn't a myth, but rather a strategy still in practice.