The last time we travelled across the country for a month, I ended up using about 50 rolls of film, which made my local MotoPhoto owner a happy man.  I've learned a lot more about photography in the few years since then, and have expanded into medium-format with the purchase of a used Mamiya 645 and some lenses.  This year we'll be spending time in Rocky Mountain National Park, Grand Teton NP, Yellowstone NP, the Columbia River Gorge, and over a week in Yosemite NP - we've got a full trip planned.

As you can see, plan on taking more photographs than last time.  The film is broken down as follow:

35mm

120 Roll Film

30 Rolls Fuji Reala 100 Print Film
10 Rolls Fuji Superia 400 Print Film
10 Rolls Fuji Velvia Slide Film
10 Rolls assorted others

60 x 36 = 2160 exposures

40 Rolls Fuji Velvia Slide Film
20 Rolls Fuji Reala 100 Print Film
8 Rolls Kodak E100S Slide Film
10 Rolls Kodak PHR-25 Print Film
10 Rolls assorted others

88 x 15 = 1320 exposures