A Large slow-moving Black Rectangle UFO Sighting in the sky over Camas WA was reported. We saw it for about 10 seconds, sometime between 8:30 and 8:40 pm April 11. Our UFO Sighting was east of PDX Airport and north of the Columbia river. It was moving to the north and completely black, no lights. It was followed or accompanied by what I think was a helicopter that did have blinking lights. We were driving west on Washington SR-14 near milepost 11 or 12. It was dusk and there was still light in the west. Conditions were clear. We saw the UFO in the distance directly ahead of us. I estimate it was 2 miles ahead of us and 3 miles east of PDX. The altitude may have been a few thousand feet. It went out of our view behind the ridge on the north side of the freeway. Its track appeared to be due north. I thought it was about the same height as the fuselage of a 737 and a bit shorter than a 737. This is based on my assumption that the following aircraft was a large helicopter, and that the Rectangle UFO was at the same distance as the following aircraft. The following aircraft was distinct and separate from the rectangle and appeared to be following it. the rectangle shape was too long and narrow to be a chinook helicopter. we saw lights on the following aircraft, but the rectangle was solid black. The edges were well-defined against the sky, which was still bright in that direction. It had 90-degree corners and no bumps, wings, lights, or rotors were visible. It simply looked like a Black Rectangle moving left-to-right. It caught my attention because it was moving too slowly to be a fixed-wing aircraft, yet it was too big to be a rotor aircraft. The second witness was my passenger. They also described it as a Black Rectangle. mufon cms# 114712 Camas Washington 4/11/21 Region has had 2,601 Reported UFO Sightings to date. Interested in reading more UFO News go to our page UFO World News.