Rocket Lab announced that it was searching for a US site to launch its small rockets back in July. It was looking at four different facilities: Cape Canaveral, Wallops Flight Facility in Virginia, Vandenberg Air Force Base in California and the Pacific Spaceport Complex in Alaska. The company made its final decision based on time for launch pad development, customizability for the Electron launch vehicle, whether it could support 12 launches a year and reach multiple orbital inclinations.
It's going to be quick work to get Rocket Lab's new spaceport up and running. The company has made it clear it wants the first launch from Wallops to be Q3 of next year, so there is a lot of work to do in a short amount of time.