I have a friend who recently moved from my fair cityPort Townsend, Washingtonto Kelowna, B.C. I regard Phil as a way-above-average cross-country mountain-biker, but he tells me the guys he has fallen in with are totally whipping is his butt on technical downhills. Man, Canadians are hardcore!" he said in his last report.
So, I expect you fall into that same category, except trail-running, not trail-biking. Actually, if youre doing a 50-miler, youre also nuts, but thats just an aside. You dont say what you wear nowsomething pretty heavy, I take it. So youd be fine in any reasonable trail-runner, but probably one with a Gore-Tex bootie, as it could be very wet in the Headlands area in December.
I like Salomon footwear, and if I suffered a severe brain injury and decided to run a 50-miler, Id perhaps purchase a pair of XA Pro 3D XCR shoes ($125; salomonsports.com) from that company. They have a mesh upper and Gore-Tex liner for a decent combination of breathability and waterproofness, sturdy toe caps, and EVA insoles with an extra nylon plate for cushioning and stability. If youre a neutral runner, these would work great.
Montrail shoes are also popular with endurance runners, and that companys Hurricane Ridge ($120; montrail.com) is a rugged but comfortable shoe that has a Gore-Tex liner, polyurethane webbing to cradle and support the foot, and a medial post that helps pronators like me but also aids stability in neutral runners. Nice shoes.
A wild card is the Teva Wraptor Stability eVent ($110; teva.com). These new shoes dont have the trail pedigree of Salomon or Montrail, but they do have some very interesting technology. A very pronounced webbing wrap can be adjusted to create a semi-custom fit. Also, they have a liner made of eVent, a non-Gore-Tex waterproof/breathable material that I think is extremely good. A urethane shank aids stability, while EVA provides cushioning. All state-of-the-art. So Id suggest you try a pair.
And good luck with the race, but I still think youre nuts.