Large, black, foil / wing flying low over field near highway in dayimte.My fiancee and I were driving north on highway 94 north of Rogers, and south of St. Cloud, when I looked to the west (my left) and noticed something gliding over a nearby field. My fiancee was driving, and I was a passenger in the backseat with her elderly grandmother in the front. I told her to take a look, but since she was driving, she only caught a short glimpse of the object. Her grandmother was unfortunately unable to turn and look at it. My fiancee told me she had seen it, and asked if I could tell what it was, to which I replied, "not sure, but it doesn't look like any kind of plane I've ever seen." As she continued to drive, the object was hovering slightly above the field at about 20 feet or so, then began to "sprint" in the same direction as our car was traveling (north). It quickly caught up to our speed (about 75 mph.), and then rose up to about 200 feet or so and stalled, then dropped to about 20 feet again, turned 180 degrees and took off in the opposite direction (south). Once more it stopped, hovered for 2-3 seconds, then turned once more and took off at a fast pace. Finally, we were to far down the highway to see anymore.I am not an aviator or engineer of any kind, but from my distance (about 200-250 yards away), it appeared to be approximately 20-25 feet from "wingtip" to "wingtip", and was about 4-5 feet wide in the middle. It was all black with no visible lights, and was in the shape of an air-foil or kinda folded wing; like an upside down, elongated U. It appeared to have no external propeller or engine, and no "cockpit" or apparent area for a passenger. I saw no people anywhere nearby in the field to make me think it was some sort of radio-controlled airplane; if it was, it was the largest radio controlled object I have ever seen! It was broad daylight at about 10:30 am with partly cloudy skies, and a slight wind from the west.I have included a map showing the approximate area we were, the direction we were traveling, the direstion(s) the object was traveling, and an illustration of what I saw. I hope this information is helpful, and I hope someone else saw what I saw.