In the mid 1950s Howard Hughes purchased 25,000 acres and containing through the 1990s Hughes Tool CompanyHughes Tool Company Nevada Operations and the Summa Corporation acquired additional holdings of undeveloped land along the western edge of the Las Vegas Valley. Much of this land was acquired for $0.25/acre ($62/km sq) since it was considered to be worthless.

In 1987, Summa Corporation exchanged 5,000 acres (20 km sq) of land adjoining Red Rock for 3,000 acres (12 km sq) of land that would become Summerlin South.

Summa Corporation began construction of Summerlin, in Summerlin North, in 1990.

In 2004, The Howard Hughes Corporation exchanged more land along the mountains for additional land further into the valley, but adjoining Summerlin South. This was followed in 2005 by approval to annex over 900 acres (3.6 km sq) into Summerlin South, NevadaSummerlin South increasing the total area in Summerlin. 2005 also marked the printing of Summerlin's first newspaper, the Summerlin News.

Summerlin is named after Howard Hughes' grandmother, Jean Amelia Summerlin.
Source: http://en.wikipedia.org/wiki/Summerlin%2C_Nevada