The Painted Hills in Eastern Oregon "are banded clays from a series of volcanic ash eruptions that formed the Cascades during the Oligocene epoch approximately 32 to 35 million years ago. These ash-laden clay and shale sediments together make up the Big Basin Formation of the John Day Basin group of geologic layers. Prevailing winds blew the ash eastward and it deposited in the lowland areas of the basin.
The colored bands represent changes in climate that occurred as they were laid down. During this period the earth’s climate was becoming cooler and drier. The reddish and yellowish layers consist of laterites, soils rich in iron and aluminum that were created in tropical climates with a distinct wet and dry season. Red soils come from a more tropical period, while the yellows are from a drier and cooler time. Dark black dots and streaks in the hills are stains from manganese nodules, likely the work of plants that fixed the mineral or from salts that became concentrated as pools of water rich in the mineral dried up. "
Is this a composite: No
Fujifilm GFX 50S, 100-200mm +1.4, 1/8 Sec @ f/22, ISO 100, Tripod, Polarizer