Which ecosystems were common in the Plateau culture area?

The Plateau culture area, located between the Rocky Mountains and the coastal mountain systems, features diverse ecosystems shaped by its varied topography and climate. The region is characterized by three primary vegetation provinces:

• Steppe and Grassland: The Middle Columbia area is defined by a steppe ecosystem of sagebrush and bunchgrass, while river valleys in the Upper Columbia also contain grasslands.1
• Forests: The Fraser area consists of semi-open coniferous forests interspersed with dry grasslands. Additionally, substantial forested areas are found at higher altitudes throughout the region, often fringed by yellow pine.12
• High Desert: The region is also characterized by high desert ecosystems, which, along with grasslands, are considered the predominant environments of the area.2

These ecosystems are influenced by a continental climate and a rain shadow effect created by the surrounding mountains, which causes most precipitation to fall at higher elevations, leaving other parts of the region relatively dry.12