Is there an overhead view?

I'm trying to get a handle on my park and what it looks like. and ideally I'd like a bird's eye overhead sort of view where I can look down on things, instead of the default which is kinda looking at them from the side. I see I can tilt the camera with some combination of the scroll wheel and the arrow keys, but I can't seem to get that working with my mouse.

Is this possible in the options somewhere? I didn't immediately see anything when I looked. (Or if there is another way for me to tilt the camera, maybe then I could do it...)