From Phoenix (80 miles - 1 hr. 30 min.) 
Travel 60 miles North on I-17 to Cordes Junction, Prescott Exit 262 
Continue West on Hwy 69, 17 Miles West of I-17, Jct. Hwy 69 & 169 in Dewey, Arizona

From Flagstaff (75 miles - 1 hr. 20 min.) 
Travel 60 miles South on I-17 to Exit 278, Cherry Road Exit
Continue West on Hwy 169, 17 Miles West of I-17 Jct. Hwy 69 & 169 in Dewey, Arizona

If you're staying in the Prescott area for more than one day, here are a few local bed and breakfasts you'll want to check out:
FX Ranch Bed & Breakfast
Cherry Creek Bed and Breakfast