Perhaps Long-tailed Jaeger

[Diane Roberts]

Hello,

I want to report my sighting of a Long-tailed Jaeger at Cherry Creek State Park Arapahoe County. Whiteish on the head, 

Barring on under wing & black tail. Will add photos. Diane Roberts, highlands Ranch

Diane Roberts

[Luke Pheneger]

Hi Diane,

Unfortunately this looks better for a gull, probably Herring but hard to say for certain.

Luke Pheneger