It continues through Kilmacrennan and enters Lough Swilly at Ramelton.

The River Lennon is a noted brown trout fishery.

[3] Salmon numbers are recovering after a UDN outbreak in the 1970's.

Other species found in the river (a Special Area of Conservation) include the freshwater pearl mussel, European otter and slender naiad.

This article related to a river in Ireland is a stub.