Porter Creek flows northwest from Keithley Mountain to the Swift River.

The area is underlain by graphitic schists and phyllites of the Upper Proterozoic Snowshoe Group and serpentinites of the Upper Paleozoic Crooked Amphibolite. Serpentine jade and nephrite jade were observed in differing locales. The north branch of the headwaters of Porter Creek exposed a number of serpentine-talc shears. The general structure and fabric of the bedrock trends to the north west and is intensely folded and faulted in places. Foliation and lineation both strike northwest and, where observed, are occasionally offset by small, crosscutting faults.

"Data from the Cariboo mining district indicate that supergene leaching of gold dispersed within massive sulphides by Tertiary deep weathering followed by Cenozoic erosion is the most likely explanation for the occurrence of coarse gold nuggets in Quaternary sediments" (Exploration in British Columbia 1989, page 147).

The recorded gold production of the Cariboo mining district was considerably greater than that of any other in the Province. The first discoveries of placer streams were made in 1860; new creeks were found quickly, and production mounted so rapidly that 1863 was the year of greatest placer output. Although detailed records of production are only available from 1874 onward, it is believed that fully one-third of the total Cariboo production was mined in the preceding fifteen years (Bulletin 28).

The Porter River valley consists of a boulder-rich postglacial outwash gravel layer reaching up to 1.8 metres thick. The extent or size of the gravel layer is currently not accurately defined. The surface channel consists of a south-southwest paleo-flow direction that parallels, and is related to, small tributaries that currently flow off the southern slope of Cariboo Mountain. Sampling of the surface gravels, near the 13P road, is reported to have averages 0.19 gram per cubic metre (Assessment Report 31471).

In 2009, test pitting identified 2 metre thick bouldery sections, measuring about approximately 35 metres wide and 200 metres long, with gold grades equivalent to 0.252 and 0.076 gram per cubic metre (Assessment Report 31471).

Some underground placer gold exploration took place along the upper part of the north fork of Porter Creek during the 1890’s. During the 1980’s and early 1990’s, near-surface gold placer exploration was performed in a localized area on the Porter Creek Valley. In 2009, a program of 17 pits, to with a maximum depth of 8.4 metres, and a 0.8 kilometre refraction seismic survey was completed.