. in october 2008 , we sold our interest in pilot travel centers llc ( 201cptc 201d ) , an operator of travel centers in the united states . pipeline transportation we own a system of pipelines through marathon pipe line llc ( 201cmpl 201d ) and ohio river pipe line llc ( 201corpl 201d ) , our wholly-owned subsidiaries . our pipeline systems transport crude oil and refined products primarily in the midwest and gulf coast regions to our refineries , our terminals and other pipeline systems