The following Salt Lake stores might have the guides. If not, the Forest Service has their own map that you should be able to get at either of the locations listed below, or at the Ranger hut at Corn Creek. The gas station at North Fork probably still sells the Forest Service Map and maybe the Guide, as might the store in Shoup about 15 miles upriver from Corn Creek (make sure to get a milk shake at the Shoup Store - mmmmm, good).
Wasatch Touring /702 East 100 South / 801.534.0905
Sid Sports / 265 East 3900 South /801.261.0300
REI store in Sandy, UT off I-25
North Fork Ranger District
11 Casey Rd. Hwy 93 North
North Fork, ID 83466