Moraine ridges on the Cascade Plateau

Moraine ridges on the Cascade Plateau

In the last million years, during cold glacial periods, many of the valleys in South Westland were filled by glaciers. This aerial photograph shows lateral moraine ridges, formed at the margins of a glacier, in the lower Cascade valley. At present the river (upper left) meanders along a broad, swampy valley, formed after the glacier melted about 12,000 years ago.