Saw this Citirail engine today, behind a BNSF unit. I hadn't heard of these before. Looking it up, Citirail is a subsidiary of Citibank.
"Citicorp Railmark Inc (trading as Citirail Express or CREX) is known for leasing locomotives to the BNSF Railway because of their crisis to move oil trains starting in 2013. The CREX (Citi Rail Express) locomotives are a rare sight to see but are becoming more popular as days go by."