River fork
Image:River [Forks at Creek Fen - geograph.org.uk - 1151461.jpg|thumb|River Fork at Creek Fen, UK]
A river fork is where a river is connected to two or more clearly and equally distinct branches. It describes both tributaries and distributaries.
A typical river fork is usually two tributaries merging, such as the Nile proper created at that of the Blue Nile and White Nile, though the term can be used when a single or main channel of a river bifurcates into distributaries, a large instance being the Mississippi at the upper end of the Atchafalaya River.
Most river deltas fork several times, occasionally forming multiple clustered, elongated islands.