I'm trying to use 3 different basemaps, Imagery, transportation, and hydrology in my data driven pages. They are saved and added to the map document as Layer files (.lyr) I would like to use both transportation and hydrology on one page, Imagery and hydrology on another, imagery on one page, and hydrology on another page. The data for the pages varies, too. But it is controlled using the "Page Definition' function. The .lyr files do not have this function available in their properties. Any suggestions?