Just a guess here, but most people don't realize how pristine and beautiful it really is here. The reason I mention that is, outdoor activities like hunting fishing, camping, boating, etc. are a huge part of people's lives here. We have massive areas of protected wilderness.
My point is, as conservative as it is here, I think even our conservatives care more for the environment than average, because they spend a lot of time enjoying it.
It's a similar thing with wildlife. The avid hunters are often the biggest protectors of habitats. Same with fisherman and rivers and streams.