I have GIS users in a field office who tell me that they have to avoid using ESRI basemaps because their internet connection is so slow. I already offer them image services of some air photo sets with ArcServer 10.3.1 which sort of substitutes for ESRI's imagery base maps. I thought, hey, I have a set of USGS quads for our state (Washington) and have ArcServer 10.3.1 running in the office, maybe I can create my own background map of topos for these users. I launched an image service of a mosaic of a small area of quads. It looks good at scales 1:24000 and larger, but starts to look crappy zoomed out much more than that. What's a source for 100k and 250k USGS topos for Washington State? Should my approach be to publish as a map service to handle the scale dependencies, so the service will switch to the appropriate map for the users map frame?