http://nationalmap.gov/ustopo/
Most of Arizona is now covered with the USGS's "next generation" topographic map, "US Topo."
In an announcement, USGS says
US Topo maps are available free on the Web. Each map quadrangle is constructed in GeoPDF® format from key layers of geographic data – orthoimagery, roads, geographic names, contours and hydrographic features - found in The National Map, which is a nationwide collection of integrated data from local, State, Federal, and other sources.
US Topo users can turn geographic data layers on and off as needed; zoom in and out to highlight specific features or see a broader context; and print the maps, in their entirety or in customized sections, on a wide variety of printing devices. Additional analytical tools are available free for download. File size for each digital 7.5-minute quadrangle is about 15-20 megabytes.