[1] The river flows just north of the Arctic Circle across a lonely, desolate area of Olenyoksky District devoid of settlements.

[1] The river flows initially northwards, bending to the NNE after a stretch, and then to the northeast.

[5] Finally it bends again to the north and meets the right bank of the Olenyok 1,351 km (839 mi) from its mouth.

[7] The Siligir has some very large tributaries, such as the 169 km (105 mi) long Onnyoo-Siligir (Russian: Онньоо-Силигир; Yakut: Өнньүө Силигир) and the 128 km (80 mi) long Siligirkeen (Силигиркээн), both from the left.

[5][1] The main fish species found in the waters of the Siligir are lenok, taimen, grayling, pike and perch.