The above posts are all relevant, but more important than laws are just using common sense and courtesy - if you are being safe and courteous, you won't get bothered, or at least be let off with a polite warning, regardless of the actual local laws.
Here in Colorado there are a number of winding roads where people like to stop and photograph, and accidents are routinely caused by clusters of cars who sometimes just stop in the middle of the road to take a picture of an elk, while mountain residents are flying past at 60mph on their way to work. The tourist traffic jam is quite the stereotype. And right or wrong, mountain locals tend to drive a LOT faster than out-of-towners since they are very familiar with the curves.
Main way to avoid problems like that is to avoid "clusters" (if there is an elk in one spot, there are probably many more in the area), find places to pull all the way off the road safely, and don't stop on corners or in blind areas. Don't be afraid to pull off in a safe area, and then walk back to the photo op - the short hike will do you good.
Have fun on your trip!