Gorge Columbia River Gorge and Falls When the walls holding back Glacial Lake Missoula would break, a flood of ice and water would rush toward the sea bursting through the Cascade Mountains and forming the Columbia River Gorge. [Show as slideshow] Leave a Reply Cancel replyYour email address will not be published. Required fields are marked *Comment * Name * Email * Website Save my name, email, and website in this browser for the next time I comment. Δ