During warm weather I see cottonmouths almost every trip to one place I hunt, but I rarely ever see them on other places I hog hunt. It just depends on the habitat. Cottonmouths like shallow still water much more than rivers and creeks which of course correlates to better frog habitat too. You'll see them on running water, but you take an area that stays flooded most of the time and they will be in abundance.
That being said, I've never had a cottonmouth strike at me unprovoked. I know it happens, but I've never seen the aggressive behavior that most people say is common among cottonmouths.
Here's a video I shot back in August that shows the typical attitude of a cottonmouth. They almost always display (open mouth) and that might be where the agressive reputation comes from, but you can see this snake won't even strike. I've done this with dozens of cottonmouths (I know I'm stupid) with the same exact results. Click on the image below to watch the video.
See yall in the Emergency Room!