Leaving a parking lot at 7:45 a,m from work, I pulled onto Hiway 160 in Pahrump, Nevada, I heading south-east. At a stoplight I looked out my front windshield at the clouds that morning. I noticed a huge shape Straight ahead at the edge of a cloud and thought for a seconed it must be a military helo because it wasnt moving. Being ex-military and having worked with helos I became immediately confused because it was totally the wrong shape. It was rectangle. Then my mind took in the distance ahead of me and I knew it was larger than anything I had ever seen in the air and not moving. As I waited for the light to change I held my thumb up and measured it with my thumbnail pressed against the window, It was wider than my thumb. I drove toward it determined to get closer, My heart started pumping like crazy and as I got closer I could see more detail on the tailend and what I presumed the right side. It was grey/blue in color on the bottom and side and the whole horizontal-rectangle rear-end was darker to black and I could see tall verticle bars (Blue/grey) from top to bottom set within the dark area all along the back. The sides and bottom seemed smooth and its edges separating top, bottom and back were sharp. It was hovering about 1,500 ft above ground just below the cloud. (I'm an ex-sky diver and can judge pretty good)As I drove closer it began to move southwest/west into the heavy cloud hanging there. It dissapeard into the cloud as I turned off Hiway 60 and Homestead Road. It had started moving down Homestead Road as it dissapeard. I parked the car and got out but it was no longer visable. It was a beautiful day that morning and it was clear except for that one darn cloud. As the cloud moved on I waited to catch a glimpse but saw nothing further. I still felt confused as to what I had just witnessed. I hesitated telling anyone, but eventually told my sister. I have not mentioned it to anyone until now. I saw something on TV about MUFON and decided to contact you.I was so Intriged by it's size that I set my odometer on the car to zero and drove back to where I originally saw it. It was exactly 3 miles to the stoplight to Homestead Road. This thing had to be gigantic! I would love to know if anyone else saw this as well. It never made the papers.