The original route down to Prescott was the Prescott & Arizona Central which started at East Seligman and went through Sullivan, Garland, Donaldson, Ross and Clearwater. Then you have a second route that ran from east Ash Fork down to Prescott (Santa Fe Prescott & Phoenix). And then there is the third route between West Ash Fork and Drake (ATSF/SFPP).
I plan on putting a map together of the first two which are abandon.
One book you might want to consider is the Arizona & New Mexico version of Railroad Atlas by Mike Walker. It is a soft cover and I think they are around $20. It provides a pretty good overview and includes a number of abandon grades. It shows quite a web of trackwork in the forest south and north of Flag.