While walking we heard a whistling sound above coming from above us we then saw the UFO

In June of 1969 my older brother and I were walking out of our apartment where we lived at the time, on the corner of 8th and Rood Ave in Grand Junction Colorado, we were walking south headed to the bookstore on 7th and Main Street when we heard a whistling sound coming from above us the whistling sound stopped the minute we looked up at it. We were in aww at what we were seeing, the UFO stood there for about two minutes I could see lights circling on the bottom and it had windows, it was probably about the the size of a one thousand square foot small house, It wasn’t dark yet it was dusk making it still very visible to see it stood below the hight of the Mountain Bell telephone building which still stands today on 8th and Main Street I would say it was around 100 to 150 feet above us, I remember trying to see if there were any figures in the windows because I could see that it was lit up inside but I didn’t see any entities. It was silver in color a round disk shape, it had no other sound other than the whistling sound and when it flew off it went south and it was gone in a flash, I am sixty seven years old now and it is something I will never forget as long as I live, we never reported it because we didn’t think anyone would believe us, we thought about reporting it, but didn’t really know who we would report it to. It was amazing to have experienced something like that in my life time.