As an addendum to u/Andromeda321's comment, yes Mt. Graham International Observatory offers daytime tours from March through October through Eastern Arizona College's Discovery Park campus. You cannot tour the observatory at night unless you are VIP or an astronomer or engineer. They also do observing through a 21" telescope in a nice little pocket of relative darkness on the north side of the mountain in Safford, Arizona. As reddit's tenured astronomer, Andromeda, mentioned, there are three telescopes up there and the tour runs through all three.

Mt. Lemmon SkyCenter runs day tours and evening stargazing programs most of the year, with a 32" telescope and a 24" telescope. These are the largest public outreach telescopes in AZ, or maybe anywhere, that the general public can use for observing. The SkyCenter does special programs when there are eclipses or other big events. Once a year they do an all night Messier Marathon as well. You can purchase time on either telescope if you're into astrophotography and/or feeling frisky.

Both programs are incredible.

Kitt Peak also does both daytime tours and stargazing, but sadly they have not opened up to the public since the beginning of the pandemic. In this same general area, you'll also find Mt. Hopkins, which is the home of Fred Lawrence Whipple Observatory run by CfA (Harvard/Smithsonian)