Much of the river is quite open and as such it provides a good fly fishing environment. Fishing on the river above Glengarnock Castle is prohibited during April and May due to the lambing season. Later in the year there can be good runs of Salmon and Sea Trout. The Plan Reservoir is high on the hills above Kilbirnie. There are a great many trout in the reservoir.
Insect life is also abundant.
Fishing at this reservoir is restricted to artificial means only no bait fishing anyone caught using natural baits will be tied to a chair and subjected to all the fishing stories of the entire committee .I would not risk it, stick to fly, lure and spinner fishing. The Auchenhove reservoir is also on the hills above kilbirnie, though it is not quite so high as the Plan reservoir. The Auchenhove is not stocked any more and similarly to the Plan it is also artificial means only the same punishments apply so beware.