I thought I start this thread insofar as there is nothing in the geography area for Montana. In Missoula limited supplies are available at Chapman Home Brew, 2328 S. Higgins, 59804, 406-549-1111. Supplies are limited with only two cultures, a few molds, vegi and calf rennet, cheese cloth, cheese wax, some drying mats and a few other things. Most of what they carry comes from New England Cheese Making. It's enough to get you started but not much beyond that. If we get enough people to go there, however, I think she's inclined to expand her inventory. It's a good idea to call before making the trip to see if what you want is there.
Milk. The Good Food Store in Missoula sells pasteurized, cream line milk from Kalispell Kreamery. I've made a number of cheeses from this and it's usually very fresh. They also carry Life Line Farms organic pasteurized cream line milk which is good but a bit pricy. You can get Life Line milk at their farm store in Victor for a bit less and usually a bit fresher.