[2] It is approximately 15 miles (24 km) long and flows in a north to northwesterly direction toward the community of Patagonia, where it joins with Sonoita Creek.

[3] Most of Harshaw Creek is ephemeral and experiences its greatest stream-flow after the summer monsoon and winter snowstorms.

Vegetation is typical to the region with cottonwood, willow, sycamore and other lesser plants forming a riparian corridor along its banks.

As a result, there are multiple abandoned mines in the area, which are a significant source of pollution.

Because of this, Harshaw Creek has a significantly higher pH level than other nearby streams.