Susan
I think your insect is a one of the shield-backed katydids...it might even be the long-legged Anabrus katydid, but I am not sure.
The shield-backed katydids do resemble robust crickets. These are found in western North America.
Most in this group are predaceous...feeding on other insects. They may also eat dead insects and some plant material.
Bugguide notes that they may bite if handled.
Here are photos of that subfamily of katydids - http://bugguide.net/node/view/284/bgpage?from=0
