It flows east-northeast through a deep, broad valley for several tenths of a mile before entering Mount Carmel Township.

The creek flows east-northeast for more than a mile before receiving an unnamed tributary from the right and abruptly turning north-northwest.

For the next several tenths of a mile, it flows alongside Pennsylvania Route 54 through a water gap.

The stream then leaves the water gap, crosses Pennsylvania Route 901, and turns west.

In March 2000, the water temperature of the stream was measured to be 10.0 °C (50.0 °F), while the specific conductance was 299 micro-siemens per centimeter at 25 °C (77 °F).

[7] In March 2000, the concentrations of recoverable sodium and potassium in Locust Creek were 8.6 and 1.9 milligrams per liter (0.0086 and 0.0019 oz/cu ft).

[7] In March 2000, the concentration of dissolved oxygen in Locust Creek was 11 milligrams per liter (0.011 oz/cu ft), but no carbon dioxide was observed.

[9] The creek cuts a water gap through Locust Mountain, revealing an anticlinal.

[2] The stream is entirely within the United States Geological Survey quadrangle of Mount Carmel.

[11] Locust Creek was entered into the Geographic Names Information System on August 2, 1979.

[13] Species such as Juncus biflorus and Platanthera ciliaris could potentially inhabit the area near the headwaters of Locust Creek.