Dillon Reservoir, sometimes referred to as Lake Dillon, is a large fresh water reservoir located in Summit County, Colorado, United States, south of I-70 and bordered by the towns of Frisco, Silverthorne, and Dillon. It is a reservoir for the city of Denver, and its waters are under the control of Denver Water. Popular ski areas are close to the reservoir, including Copper Mountain, Keystone, Arapahoe Basin, and Breckenridge. == History == In 1859, a large party of gold-seekers led by Ruben Spalding discovered gold near the headwaters of the Blue River, which prompted a population surge in Summit...

A heat pump is a system used to heat or cool an enclosed space or domestic water by transferring thermal energy from a cooler space to a warmer space using the refrigeration cycle, moving heat in the opposite direction in which heat transfer would take place without the application of external power. When used to cool a building, a heat pump works like an air conditioner by transferring heat from inside the building to the outdoors. When used to heat a building, the heat pump operates in reverse: Heat is transferred into the building from the outdoors. Common heat pump types are air source heat...

The Great Migration, sometimes known as the Great Northward Migration or the Black Migration, was the movement of six million African Americans out of the rural Southern United States to the urban Northeast, Midwest and West that occurred between 1916 and 1970. It was caused primarily by the poor economic conditions as well as the prevalent racial segregation and discrimination in the Southern states where Jim Crow laws were upheld. The historic change brought by the migration was amplified because the migrants, for the most part, moved to the then-largest cities in the United States (New York...