Lockie (Boulder) Creek initially flows southward along the west flank of Boulder Mountain for 2.3 kilometres, and then continues eastward for 4 kilometres, entering Otter Lake 4.5 kilometres north of the town of Tulameen.

The creek first flows for 3.5 kilometres through a narrow valley, then enters a canyon, 2.3 kilometres long, before flowing over an alluvial fan on Otter Lake, 0.5 kilometre wide.

At the Boulder Creek Placer occurrence, gold was recovered from gravels in the lower 2.4 kilometres of the creek, and also in a few places above the canyon. One nugget found in 1887, likely the largest gold nugget from the Tulameen district, weighed 1400 grams (Minister of Mines Annual Report 1898, page 1111). Unlike most other streams in the district, no platinum was recovered from the creek's gravels (Geological Survey of Canada Memoir 26, page 136).

The creek was worked intermittently between 1886 and 1909. Estimated production for 1886 to 1900 is 32,000 grams of gold.