In general, mid October marks the time when the Koyukuk river, which flows out of the Brooks Range, freezes over. The ice formation on the river creates interesting patterns and shapes during its freeze-thaw-freeze phase. The crystal clear water seems about as pure as water can get. This picture was taken on Oct 14, at almost 11:00am, which shows how late the light arrives upon this landscape in the arctic. A few days later, the river was nearly 100% frozen over.