What website or other sources can I find the cheapest and lowest airfare in USA I’m going from Detroit to Utah
Nearly every travel website offers the same deals as airfares are regulated by the airlines. In fact, by purchasing on travel websites, you are likely to pay more by way of booking fees!
You can use websites like www.travelocity.com and use the flexible travel dates functions or the " +/- 1 to 3 days" function which lets you search for the day you want but also 1 to 3 days before and after. Once you find an airfare you like, write down the flight numbers and such and go directly to the airlines website and book. You will get the same fare and you will not have to pay a booking fee. In fact, many airlines offer bonus miles in their frequent flyer programs just for booking online.
If you need to a hotel room then using a travel site like travelocity may get you a better deal as not all airlines offer packages directly. In fact, one time I went from Austin to Chicago and the cheapest airfare I could find was 600 for the dates I needed. But by booking with 3 nights at the Holiday Inn downtown, the best Holiday Inn in Chicago, I only paid 445, even though I could have stayed with my mom.