Here’s one interesting photo of a triangle-shaped craft that was taken over Marana in Arizona, back in May 2015.
Witness report: On vacation playing golf, watched and heard F18’s flying around courses a lot, took picture of friend and saw craft in photo it made no sound unlike F18’s, it was so far off I didn’t think it was a craft, (maybe a bird) plus made no sound so I went back to playing golf. Later that evening was looking at image with friend and we decided it had to be a craft of some kind. I worked for General Dynamics for few years and watched a lot of military aircraft flying and this looked nothing like any I have observed. It appeared to be ascending in a straight line at about a 20 degree angle.
Author (source: MUFON)