The first was on September 16, 2010 and the second was October 26, 2010.
MUFON state director Marilyn Carlson in Yukon says she talked with the witnesses in both events.
In her report to MUFON on the September incident, Carlson says the unidentified witness told her about spotting an elongated triangle-shaped object over a field near Stigler.
She says they checked out the field and found a circular area in the middle of the field "with green grass on outer edge and center has a bare spot."
The witness told Carlson the lights on the object "were white and went down the side of the triangle and it was hovering."
In her report to MUFON on the other incident, Carlson says two witnesses spotted an elongated triangle right above them at about 10:30 p.m. on October 26, 2010.
They told her the object was the size of a city block and blocked out the stars and sky, "It was black with single rotating white lights on each corner of the object."
Carlson says the two witnesses said the object was similar to a drawing MUFON provided.
Robert Sheaffer, with BadUFOs.com, says he's skeptical of the reported UFO sightings and says you can't automatically connect the bare spots to the UFO's.
"If that were true then UFOs must have been practically everywhere. My lawn has some terrible, persistent bare spots. It never occurred to me that this might be from a UFO! I think if you investigate the drainage, soil conditions, etc. for this "UFO circle", you'll find a much better explanation there," Sheaffer told the News On 6 in a statement.
MUFON officials say they get about 500 sightings a month with only 20 percent of those being credible sightings. MUFON says Oklahoma had 12 UFO sighting reports in October 2010.
They say the two Oklahoma sightings in September and October are considered credible.
Oklahoma's Own Newson6.com is proud to provide Oklahomans with timely and relevant news and information, sharing the stories, pictures and loves of Oklahomans across our great state including Tulsa's Own and Green Country's Own.