It's hard for me to talk about this. I'm an oil field worker, and also a truck driver. I haul crude oil for a living. My job takes me to remote places out in the middle of nowhere. I drive out to oil wells, test oil, take samples, and if the oil is good, I buy it, load it up from the well and put it in my tanker and drive it to an offload facility and sell it. I have a class A license. I've been hauling crude for over three years now in Colorado, Wyoming and Nebraska. Two summers ago I was out in a remote part of Colorado, a place called the Pawnee Grasslands, right on the Colorado and Wyoming border. There is nothing out there, just open space, and a lot of oil wells. The closes towns were Grover Colorado, and maybe Herford Wyoming. It was close to sunset, I was out at an oil well called the "critter creek 03-04h", its an EOG oil well. I had pulled up, went on top of the tanks, took some samples, they looked good, so I then hooked up to the tanks and started load up. About 5 to 10 mins later I was sitting in the cab of my truck, which was facing west, when I saw something coming over the horizon. At first I thought it was nothing, maybe a plane or something. As it started to get closer though I could tell it was not a plane. I could see then that the object was round in shape, but could not make out a color yet because it was coming at me from the west and the sun was shining behind it. I started to think, maybe its one of those big balloons filled with helium, the kind u might see floating at a car dealership. Quickly I dismissed this, the wind was blowing hard at the time, pushing down from the north to south, which is very common for this area, yet this object was not affected by this cross wind at all. It stayed on a fairly low and flat course headed straight for me. I'm a grown man, but I began to get a little nervous and even a little freaked out by this thing, but at the same time I was excited as well. I started saying out loud to myself, what the heck is that, what the heck is that? By this time it was getting very close too me and my rig, I could see that it was blue in color, just as I could kinda make out the color, the pump on my truck shut off. My engine was still running on my rig, but my hydraulic lines that operate my pump for loading crude oil, called my PTO, shut down. I had my window down and was still sitting in my rig at the time, I said out loud, what the heck?? I grabbed my cell phone and hopped out of my truck. The object was almost on top of me at this point. I quickly ran with my phone to the ladder to climb on top of the tanks, which are 20 feet tall, to get a better view. When I got to the top on the cat walk the object was coming over head. This was the closes I ever got to this object during this hole experience. I could see that this thing was perfectly round. I mean perfectly round! It was a bluish gray in color, if that makes any sense, kinda dull. It was very strange because the sun was setting, the sky was all orange from the sunset, yet this thing was not reflecting any of that color or light at all. Not shining, nothing! It was almost like tho object was not flying through the air, but the air was going around it?? There were no lights, no windows, no lines on this thing, nothing. Perfectly round sphere and smooth. There was no sound at all, in fact, I remember it kind of getting more silent as this thing passed over me. I remember thinking, pull out your phone and take a picture. But as soon as I said that to myself, all at once I thought, no, don't worry about it? This really bothers me when I think about it, that's not like me at all to not wanna take a picture? I mean, that's why I grabbed my phone. I can't explain why I didn't take a picture when it was coming over me? I know that I was freaking out a little, scared a little, but still, it makes no sense to me at all why I thought that? I stood there in awe as this object passed over me making no sound at all. I just kept thinking to myself, what the heck is that? It never slowed down or sped up, it never moved off of its course. I watched as this object moved over head and steadily move to the east and finally disappeared over the horizon. This is kinda the weird part that I haven't even told my wife, I was on top of the tanks watching this thing when it passed over me and disappeared over the horizon. The next thing I remember after it moving out of sight is standing next to my truck with the pump running. I looked at my gauge on my tanker and I was almost fully loaded up. I think maybe I was in shock or something and don't remember walking down the ladder from the top of the tanks to my truck. Even stranger, when I finished loaded and put everything away and was getting ready to leave, I climbed in my truck and found my phone sitting on the drivers seat? I'm sure I had it in my pocket? I think this thing got me all worked up and I must have been in shock or something because I don't remember getting to my truck or getting into my truck prior to standing next to my pump? I've told only my wife about this object, and never about me being in shock. When I told her what I saw, she told me never to tell anyone else about this and to just forget about it. For the last couple of years that what I've tried to do, but its always in the back of my mind, what did I see that day at sunset? What the heck was that thing? The best I've ever been able to come up with is maybe it was some kind of military object. After a lot of thinking and exploring and reading, I have found out that there is a military air force base east of there and that this area where I was at and the object was heading is full of nuclear missile silo's. Maybe its some kind of defense thing or something? I just don't know? I will say, it feels good to finally tell someone my story. It's been hard for me keeping this thing to myself.I thank you for this website, as I feel a lot better telling someone. If you have any idea what this thing was, or anyone else has seen anything in this area similar, please let me know. If you have any questions please feel free to contact me through my email and phone if u feel necessary. Again in sorry that I can't pin point that very day, but I know the date provided is close. Thanks again