Castilleja Lake is located in the Skoki Area of Banff National Park. This lake does contain some fish which apparently are Brook trout. I did see some minnows near shore so I can confirm the existence of fish here but I didn't catch any. It is also likely that the fish in Castilleja are pretty small given the elevation and size of lake. The water in this lake is fairly silted which gives it the nice color but seeing any fish was not possible.