The time line of the Kitselas Canyon and the surrounding region has been broken down into six cultural phases.
The earliest phase is known as the Bornite Phase. This phase lasted from about 5000 BP (before present) to about 4300 BP. This phase was found only at the Paul Mason Site. Some of its characteristics include an assortment of flaked tools, particularly microblades and an absence of ground tools.
The next phase, the Gitaus Phase, lasted from about 4300 BP to 3600 BP This phase was recorded at the Paul Mason Site, as well as Gitaus. Characteristics of this phase include cobble tools, spalls and ground tools.
The Skeena Phase is only found at the Gitaus site. It dates from 3600 BP to 3200 BP. In this phase the tool assemblage changed, giving an increase in bifacially flaked tools. Bifacially flaked tools are those that have been flaked on both sides. It is likely that the people who made the tools in this phase spent more of their time hunting land mammals.
The Paul Mason Phase, found only at the Paul Mason Site, dates between 3200 BP to 2700 BP. This is the first phase that shows permanent settlement at the canyon. All the other phases to this date seem to indicate summer camps. It is possible that the inhabitants of those phases spent their winters on the coast. The Paul Mason Phase also shows a decrease in flaked and chipped tools and increase in ground tools.
The Kleanza Phase, only found at Gitaus, dates from about 2500 BP to 1500 BP The tool assemblage for this phase closely resembles the tools found in the Paul Mason Phase. This is a good indication that their subsistence activities were similar. However, some new tools were also found. They include net sinkers and groundstone adzes. Adzes are used in woodworking Some status goods were also located during this phase, such as labrets. A labret is what is known as a lip plug. Labrets were worn by high ranking women; an incision is made in the lower lip and a small stone called a labret is placed in the hole.
After the Kleanza Phase, there is a gap in the archaeological record. The final identified phase began 250 years ago. This phase is known as the Historic Phase. This phase is only found at Gitlaxdzawk and Gitsaex, the two historic villages at the Canyon.