I'm not famliar with your area, Ty, but I'd suggest you start by taking note of the butterflies you see in your area, identify them, then find out what their host plants are.
If you see, say, a western tiger swallowtail, you could plant cottonwood, ash, willow, alder, or aspen trees to attract the egg-bearing females. If you should see an anise swallowtail, you could plant members of the parsley family, such as dill, fennel, parsley, etc.
You'll need a good field guide. My favorite is Butterflies of North America by Brock and Kaufman. It has excellent pictures that make identification easy, and it includes a general list of the host plants of each species.
You'll need some nectar plants. You can't beat butterfly bush for a start - it appeals to every butterfly.