Many of these large streams have excellent sulphur mayfly hatches and I use the same dry flies I use on the mountain streams. On streams such as Big Stoney Creek west of Edinburg, Back Creek and the Jackson I use the Murray's Sulphur Dry size 16 as a searching pattern even if the hatch is sparse. However, I always try to fish until dark so I'm taking advantage of the concentration of both the duns and the spinners.
The Department of Game does not stock these streams through the summer months. All of the local stocked trout streams are currently clear and fishable.