So lights seen in Arizona and California recorded, and as I believe
@TenEightyOne usually makes note of the quality, these have a quite good quality to them. A man in Parker Arizona traveling toward Quartzsite AZ saw these, I heard about it on the local news. What's interesting in a group in El Centro California also saw similar lights, I've been to both places (El Centro I have family), so it's strange to see this type of thing. However, I will note that El Centro and Yuma both have Marine/Naval air stations, that operate in said area, the YPG (yuma proving ground U.S. Army) base is stationed between Yuma and Quarzsite as well.
I personally have seen similar lights to what the viewers have when I lived in Yuma, they appeared in a triangular pattern as such before coming together and flashing out into the dark of night. I have also seen amber military flares though never out toward the region of Quartzsite, that's not to say they don't happen out toward Blythe/Quartzsite area, just never personally heard or seen this.
Most flare drops are usually done in the Goldwater test range by the Marine base in Yuma. Also once again I dislike secureteam, but they usually have this stuff when it is difficult to find later from local media who originally broadcast the subject.