Large teal circle followed by helochopters hours later.Over a year ago, I believe I saw a UFO. However, due to that night's events and how tired I was, I could be mistaken. The night in question took place just after an article was released about US and Chinese naval ships dealing with USOs in the pacific off the coast of San Francisco. I was listening to Clyde Lewis in Portland talk about the article and discuss various UFO sightings. This is part of the reason I think what I saw may be wrong. There is also the fact that near the beginning of my shift, I was working as a security guard at an apartment complex in Portland, there was some sort of big celebration taking place with giant search lights moving across the sky. Additionally, I also hallucinate when I get very tired, however, I don’t recall be that tired during that particular night.Now, the search lights started their thing as soon as it got dark. They were white beams and would reflect off the clouds when they came across them. Nothing spectacular about them and they were out after a few hours. Clyde Lewis’s show was still going for since time after they went dark. His show was also still going when I saw a new green search light going across the sky. At least I thought it was a search light as I watched it travel from the eastern horizon and disappear in to the west. What changed my mind into thinking it was a UFO is that it traveled in a straight line, never returned and was clearly traveling above the clouds since it would momentarily disappear when it passed by one. Thus, I am sure it was not the beam from a search light. Also, the suspected UFO was moving very fast and seemed very large. Also, its color was a solid bright teal. So basically I think I saw a teal circle of light UFO.Now, had I just seen that light I could have written it off. But, what happened a few hours later makes me wonder. Clyde’s show was over and I had switched to coast to coast. So the occurrence happened sometime after midnight PST. Now this occurrence was the unusual appearance of 4, presumably black hawk, helicopters flying fairly low and over the same path the teal light took. There was one difference though. The 4 helicopters seemed to stop over the Willamette River for a couple minutes before separating. One headed south. Another north. The third went North West and the final one stayed above the river for a few more minutes before continuing west.There you go. That’s my potential UFO sighting.((NUFORC Note: Witness indicates that the date of the sighting is approximate. PD))