Heirloom seed varieties in Davis County
I could find no heirloom varieties in your "Home Vegetable Garden Variety Recommendations for Utah." The heirloom reference I used was William Woys Weaver's "Heirloom Vegetable Gardening; A Master Gardener's Guide to Planting, Seed Saving, and Cultural History" (1997). Of course, your list contained numerous hybrids, but none of the open-pollinated varieties were identified in Weaver. Perhaps, my question should also be about the differences between open-pollinated and heirloom varieties because I originally supposed there were no differences.
Davis County Utah
You're right, there is no difference. Heirloom varieties are "open-pollinated". This website, has some more information: http://www.halcyon.com/tmend/define.htm.
Not sure what else you are asking. If you are looking for specific recommendations, please email Utah State University Extension's Vegetable Specialist, Dr. Dan Drost at firstname.lastname@example.org.