The growing season generally last 45 to 120 days, but as long as 140 days in some lower valleys. Surface Water Characteristics. There is a high frequency of rapidly flowing rivers and streams during June. Rivers follow faults in the crust over the Kettle Dome to the west. The Pend Orielle and the Columbia Rivers both run from the north to the south, with tributaries entering from the northeast and northwest predominantly.
Most creeks flow through glacial outwash and debris material within narrow valleys.
There are many glacial lakes and wet meadows associated with the last retreat of the glaciers in northeastern Washington. Historic fire events have changed a large portion of the forest. Changes are periodic and range from high intensity, high severity, continuous fires to low severity, infrequent fires. Composition and successional sequences of some communities has changed because of harvesting practices and the introduction of animal species into the valleys. Wide fluctuations in precipitation and temperatures for periods of years result in significant changes in biological communities.