My wife and I were traveling North on Hwy 169 just North of Garrison, Mn. My wife was driving and she pointed out what appeared to be headlights of a plane and said something to the effect of "look how low he is flying". I looked to the Northwest of our line of travel and saw what appeared to be one plane following another very low over the trees. I said something to the effect of "there are two of them, and look how close they are following each other. They must be military or maybe helicopters". The first object crossed Hwy 169 in front of us and disappeared. We passed right under the second object and I stuck my head out of the passenger window and initially was looking straight up at it. I could see it silhouetted against the stars. It was at this point that I realized that it wasn't any normal plane, or helicopter. It looked similar to the outline of a stealth jet. The object went out over Lake Mille Lacs. It was moving too slow to be a plane and it wasn't making any noise. It only had green lights on its underside and it wasn't shaped like a plane