Embodiment of system, an apparatus and process for delivering proppant to a well site has a trailer with a bed thereon and at least one track of rollers extending in parallel relationship to the longitudinal axis of the trailer. The track of rollers extend substantially for an entire length of the bed of the trailer. At least one proppant container is translatably positioned on the track of rollers. The proppant container is movable along the array of rollers from one end of the bed to an opposite end of the bed. A bin can be removably positioned below the bed of the trailer in a position rearward of the front end of the trailer and forward of a rear end of the trailer so as to allow the proppant container to discharge into the bin. A conveyor is cooperative with the bin so as to move proppant from the bin to a location at the well site.