How can I obtain the mailing addresses for the. IRS and Utah State tax commission so I can mail out my returns and insure I'm sending them to the right place

Please look at below links. The FED IRS address depends on whether you are sending payment or not:

https://www.irs.gov/uac/where-to-file-paper-tax-returns-with-or-without-a-payment

And here's Utah information:

Utah State Tax Commission; 210 north 1950 West; Salt Lake City, Utah 84134

http://tax.utah.gov/forms/current/tc-40inst.pdf