Summary : A small UFO we chased in a Piper Cherokee plane. Object led us in a circle then passed below us.Four of us (3 pilots) just had landed at the Gogebic County Airport, and while taxing back toward the hanger noticed a flashing yellow light about 2 miles southwest of the airport. We took off again on runway 27 and headed straight at the object. It continued to flash a yellowish white light in no particular sequence. As we approached it, it headed east (our left). We turned to follow it, but it kept staying off our left wingtip. It led us in a complete 360 degree turn. It then headed east along a range of hills. It entered the landing pattern for the airport at 800 ft above ground level. We followed it. It completed the downwind pattern, but after turning onto the dogleg, instead of entering final approach, it veered at a 45 degree angle and passed underneath us. We were at 800 feet above the ground at the time, in the downwind leg of the landing pattern. When we finally got turned around, the object had disappeared. Witnesses on the ground with whom we were in !radio contact with claimed the object passed above us, then just zoomed upward at a steep angle and disappeared. We knew the object passed beneath us. The object appeared to be a yellowish-white light about 5 feet in diameter. When it passed below us, it did not appear any larger and there was no sign that it may have possibly been larger. Three of us in the plane were licensed pilots, one a commercial airline pilot. Witnesses on the ground included the airport manager, a local government official and two other pilots. This encounter was reported to the University of Colorado UFO study which was the offical reporting place at the time. I received a letter from the project coordinator, Mr. Robert J. Low on March 8, 1968. He stated that the report would be included in the their active file. I was informed a few days later by the airport manager, that he had received a telephone call from the University of Colorado asking for more details about the sighting, which he pro!vided. He was also asked about us, were we creditable witnesses, etc. He stated that he told them that we all were good honest witnesses. I never heard anything more about this other than a small article in the local newspaper. I was wondering if you have ever had any reports similar to this one. If you have, please advise me of them and where I can read them. If you need any more information, please contact me. I have the letter from the University of Colorado and several other items concerning the sighting.