A Landscape Forged by Acid and Iron The orange, red, and yellow earth of the Kootenay Paint Pots is the result of a complex geochemical process originating deep underground. Cold, acidic groundwater works its way through ancient rock layers, dissolving minerals and becoming high in iron.%%CITE_1%%%%CITE_2%% The source is likely a large, unexposed deposit of pyrite-rich ore connected to a major geological feature called the Kicking Horse Rim.%%CITE_3%%%%CITE_4%% This water emerges from three main spring outlets with a very low pH of around 3, making it highly acidic.%%CITE_1%%%%CITE_3%%
When this iron-rich water reaches the oxygen in the atmosphere, a rapid chemical reaction occurs. The dissolved ferrous iron (Fe²⁺) oxidizes into insoluble ferric iron (Fe³⁺), which then precipitates out of the water. This process creates vast deposits of iron oxyhydroxides, staining the clay and soil. The dominant mineral formed is goethite, which creates the yellow-to-brown ochre color. Different shades appear based on the exact mineral composition and hydration levels. The water also carries high concentrations of other metals, including zinc, lead, and arsenic. Despite the cold temperatures, these unique chemical conditions support a community of extremophilic bacteria and at least 14 species of algae that thrive in the metal-rich environment.
A Source of Pigment for Millennia
For thousands of years, the ochre beds have been an important site for Indigenous peoples, particularly the Ktunaxa and Secwépemc. The Ktunaxa have occupied the region for more than 10,000 years and know the site as "Namita qakxaǂ ʔitkniǂni ʔaknusmi," meaning "Paint made from red clay". They harvested the iron-rich clay to create pigments for several purposes. The collected ochre was kneaded, flattened into cakes, and baked. This hardened material was then ground into a fine powder and mixed with a binder like animal fat or fish oil to create durable paint.
This paint was used for pictographs (rock paintings), ceremonial body decoration, and to color clothing and tipis. The ochre from this specific site was a valuable trade good, exchanged between different groups across the continent. In the early 20th century, settlers attempted to mine the deposits commercially, shipping the pigment to Calgary for use in paint manufacturing. This operation ceased when Kootenay National Park was established in 1920, preserving the area. Remnants of this brief industrial period, including old mining equipment stained bright orange, can still be seen along the trail.