As you drive through on the thousands of miles of Montana's scenic roads, be aware of your speed. After living in the Treasure State for all these years, I just learned that Montana has a 'default' speed limit of 25 mph.
A friend of mine received a speeding ticket traveling down the road from Big Mountain Ski Resort to Whitefish, MT. He was only traveling 35 mph, and was ticketed for 10 miles over. When he complained that there were no posted speed limit signs, he was informed that any road in Montana that doesn't have a posted speed limit is a 25 mph zone.
This may be common knowledge to many people, but it was the first time I (or my friend) have heard of this 'default speed limit' law. So... be careful out tthere and watch for posted speed limits.