Birch Creek flows south into Pine Creek less than 2 kilometres west of Surprise Lake, about 15 kilometres northeast of the community of Atlin. The creek is about 9 kilometres long and was worked for about a 3.5 to 4 kilometre length starting from about 1 kilometre above its junction with Pine Creek. Hydraulic methods were used a great deal on Birch Creek and 386,859 grams of gold were recovered on the creek from 1896 to 1945 (Bulletin 28). It was known for its unusually coarse gold. It is the 8th largest producer of placer gold in the Atlin camp.

The creek is underlain along its entire length by Upper Paleozoic mafic volcanic and ultramafic rocks. The volcanic rocks belong to the upper Mississippian to Permian Nakina Formation (Cache Creek Complex), and comprise mafic, dark grey-green greenstone. Upper Mississippian to Permian ultramafic rocks (Cache Creek Complex) are commonly altered to talc and serpentine. The creek is very near the southwest margin of the Late Cretaceous Surprise Lake batholith (Surprise Lake Plutonic Suite). There is also some limestone (sometimes metamorphosed to marble) and argillite of the Mississippian to Triassic Kedahda Formation (Cache Creek Complex) which overlies the Nakina Formation in the upper parts of the creek. Like many other creeks in Atlin, the miners process the top 1.8 to 2.4 metres of bedrock and get good gold recovery from it.