Ripples in red argillite, NPS photo, J. MohlhenrichSeam of quartz, NPS photo, David RestivoMountains from Lake McDonald, NPS photo, David Restivo

The interplay of numerous geological processes has helped to form the Crown of the Continent and continues to inspire wonder in visitors. The uplifted mountains along the rugged ridge of the Continental Divide split the Crown ecosystem into a lush western half and a dry eastern half. The landscape is defined by sweeping U-shaped, glaciated valleys bounded by dramatic, vertical rock faces topped by peaks of primitive rock. The numerous streams and lakes follow the paths of former glaciers that descended from the Continental Divide and continue to move large amounts of soil and rock.

Geological features include scoured streams where past prospectors found gold, clear glacial lakes that continue to amaze visitors, and mountain valleys that made railway and highway passage possible. The landscape of the Crown remains a very active place and changes continue to occur through natural processes such as weathering and erosion, landslides, and infrequent and minor earthquake activity.