"Light" flew as wingman to commercial flight.Klamath Falls is a navagation point of a North/South Commercial Air traffic corridor. As such there is a large degree of air traffic regularly seen in this vicinity. There is a wide Military North/South military corridor begining about 45 miles to the east of here. Another N/S commercial flight path traverses Medford, Oregon to the west, approximately 55 air miles. Commercial aircraft was first noted directly over head at approximately 21:57 headed south at 180', with a bright "light" approximating the appearance of a satellite, with out any navigational lights, directly to the starboard side matching it's speed. If it is assumed that the commercial traffic was at 30,000 feet, than the object was approximately less than one mile from the aircraft. In lay terms, it was the distance of the width of your thumb held at arms length. It matched the flight path of the commercial until lost in the haze due to a forest fire to the south, at approximately 4 to 5 degrees in elevation, still on a 180' path, at 22:02. Magnitude of the object did not diminish, except once, for less than a second, in which it did dim. It is difficult to imagine that this was a coincidence of a polar orbit satellite appearing to "match" the flight path of a commercial aircraft. The other witness was called out to view the object, but she is not trained in aerial observations.