Klamath Falls, Oregon is located on the western edge of the Basin and Range physiographic province on the east flank of the Cascades approximately 30 miles north of the California border. It is located in a graben structure about 10 miles wide flanked by horst blocks rising over a 1,500 feet with steeply dipping normal faults trending in a northwest southeast direction. Upper Klamath Lake, a shallow body of water about 35 miles long, dominates the graben