Imperial Reservoir Imperial Reservoir The Imperial Reservoir is an artificial lake formed by the construction of the Imperial Diversion Dam across the Colorado River in the Lower Colorado River Valley of Imperial County, California, and Yuma County, Arizona. A component of the Imperial National Wildlife Refuge, the reservoir is northeast of Yuma, Arizona. Dry washes are the major watershed feed systems to Imperial Reservoir. The next upstream major watershed feeder is the Bill Williams River from western Arizona. Upstream on the Colorado River, the basic feeder watershed to Imperial Reservoir is the Havasu-Mojave Lakes Watershed, of Lake Havasu. Two dry wash watershed
Imperial pigeon al., and followed here. Four species of imperial pigeon are found in Philippines and Sulawesi. All have a distinct pale band across the centre of the tail, and a rich green or purple dorsum. This grouping shares characteristics and distribution with "Ptilinopus", and forms a link between the genera. The pink-belled ("D. poliocephala") and the white-bellied ("D. forsteni") imperial pigeon are similar and allopatric species. The Mindoro ("D. mindorensis") and the grey-headed ("D. radiata") imperial pigeons differ in size but are otherwise similar. The spotted imperial pigeon ("D. carola") is sympatric to "D. poliocephala", and though smaller, short tailed and