Lake Mead, Nevada
The area around Las Vegas was never hit by the ICBMs, like Denver, New Orleans and Dallas, because of anti-ICBM laser defense systems. As a result, few mutations took place and Lake Mead was unaffected. The Lake became the most prized possesion of the Mohjave like Vegas and Hoover Dam. The city of Port Mead is located on it's banks, in Callville Bay. Nellis AFB raised the B-29 in it's lakebed and mass-produced it.