I will add that you can also get Sheepherder's bread at the Schat's Bakery in Mammoth. (The two Schat's Bakeries were originally owned by brothers who had a falling out. The brother in Mammoth got a divorce a couple of years ago and the ex-wife got the bakery...the two bakeries now work together again.)
Since trout don't seem to get up that early, we time our visit to the bakery around 10:00 am for turkey sandwiches to go...real turkey not deli turkey and on Sheepherder's bread of course!
We haven't found the fishing too profitable on the road out of Tom's Place along Rock Creek. However, if you do camp along this road, the very last campground before Rock Creek Lake is very small (meaning that large RVs with generators can't fit) and within walking distance of a small resort (Rock Creek Lodge) which has showers for rent and serves meals. At the lake itself is Rock Creek Lakes Resort:
http://www.rockcreeklake.com/resort/
Get there early in the morning (but not too early) and buy a couple of pieces of pie to have later...they make all of their own pies and sell only by the slice...too many people were getting upset that all of the pie was gone before they arrived!