RkyFlight 
4K
N785SK (visible on foremost aircraft)
United Express
CRJ7
DEN/KDEN
Bombardier CRJ-700/900 Series (most visible aircraft are CRJ700s; distant tails may include CRJ550 and E175 mixed in United Express livery)
A busy winter morning ramp scene at Denver International Airport with multiple United Express CRJ-700s and other regionals lined up at Concourse B.