Not a common murre. Midway between gray jay and raven in size and posture, shape. Not a gull at all. At first I thought it was a raven from its song, which could have been a raven having some fun, and from first glance it was ravenlike until I noticed the white. In flight it shows a lot of white. The color is coal black and brilliant white in large solid areas, wings and body. There may have been a second one, but probably not. Thin bill, moderate length. Seemed shy and uncertain. Almost seemed tame, flew off slowly, but a big, strong bird about half the weight of a raven.
Found the following mention of a white raven in Fairbanks: (http://www.ewebtribe.com/NACulture/articles/ADNWhtRavenFbx.htm). Maybe it had some mixed color offspring.
Other birds that came up in my search include the swallow-tailed kite. Large black and white hawklike bird 22 inches long, weight about 40% of a raven. But it would be thousands of miles out of range.
Maybe you have an accidental from Asia. (Watch out for the bird flu.)
You might try ABR Inc. there in Fairbanks. They've got some bird experts on staff.
I see that I needed to put a space after the htm in my link.
http://www.ewebtribe.com/NACulture/articles/ADNWhtRavenFbx.htm