Where do you live in the foothills? I have a lot of climbs that I can share with you. I'm sure Sagebum does too. Basically, you want climbs that are long and fairly steep (5-8%) You can always do Iowa Hill - 13% average for 1.75 miles. If you have time and want a hard series of climbs, here is my recommendation. You can do all, or a subset of them.
http://www.bikecal.com/bill/columns-....asp?bRecNo=13
You will be way over prepared if you can do even a few of these. The Bisstlecone climb to Schulman Grove is the first of three climbs on the White Mountain Double. 20 miles and 6100' of climb, starting at 4000'. After you have completed it, you only have another 160 miles to go.
