The Indigirka forms a large
delta, consisting of a number of streams (each one being labeled on Russian maps as a
протока (protóka) (
river arm)) and islands. About before reaching the East Siberian Sea (), the river splits into two major northeast-flowing
streams. The left (westernmost) arm is known as the
Russko-Ustyinskaya Protoka; the right arm, the
Srednyaya Protoka (Russian for the "Middle Arm"). Further downstream, the third major arm, the
Kolymskaya Protoka splits off the
Srednyaya Protoka as its right (eastern) distributary, thus justifying the "middle" moniker for the Srednyaya Protoka. While
Srednyaya Protoka means the "Middle Arm", the names of the main western and eastern arms indicate their relative location as well. The
Kolymskaya Protoka, or
Kolymskoye Ustye is the arm one located on the eastern side, i.e. the "Kolyma side" of the delta (the arm closest to the
Kolyma, the eastern neighbor of the Indigirka). The
Russko-Ustyinskaya Protoka, apparently known earlier as simply
Russkoye Ustye is the arm one located on the western side, i.e. the "Russian side" of the delta (meaning, the side closest to the (European) Russia). These days the name of the
Russko-Ustyinskaya Protoka appears as if it were formed from the name of the old Russian village
Russkoye Ustye situated there, but originally the opposite is likely to have been the case, the village is named after the river arm (the
Russkoye Ustye) on which it was located. Several flat islands are formed by the channels of the delta. Listed from the east to the west, the major ones are: •
Usun-Ary lies longitudinally along the coast east of the Srednyaya mouth. It is and wide. •
Uparovskiy Island lies completely detached offshore from the Srednyaya mouth. It is about long and 1 km wide. •
Ploskiy Island is the farthest offshore of a cluster of islands at the Srednyaya mouth. It is C-shaped and about 3 km long. •
Bolshoy Fedorovskiy lies between the two mouths of the Indigirka. It is 6 km long and has a maximum width of 4 km. •
Vkodnoy and
Oleniy islands lie right at the Prot. Russko Ust'inskaya mouth . Both are of similar size, about 4 km in length. •
Krestovyy Island lies quiet isolated directly to the south of the
Lopatka Peninsula, offshore to the northwest of the main Indigirka mouths. It is 6 km long and 1.6 km wide. ==See also==