"It's a once in a generation, historic opportunity for South Dakota," Thune said, adding that it will ensure Ellsworth remains a vital part of the nation's military.
The base, located near Rapid City, is already one of the largest employers in the state. According to a 2017 estimate, it had an annual economic impact of over US$350 million.
Ellsworth faced the possibility of closure in 2005 when it was briefly put on the Pentagon's list of military bases that should be closed or relocated. But since then, South Dakota politicians have worked to keep it on the shortlist of sites for the B-21 bomber. The Air Force had announced in March 2019 that it was leaning towards the base as the location to develop its B-21 Raider programme.
Rounds credited West River communities for rallying to make sure the base stayed open. He added the development would create a ripple effect of construction for schools, infrastructure, and housing.
The Republican senators emphasised that it will be an important piece of the United State's military rivalry with both Russia and China. The bomber is expected to have a range long enough to attack targets on other continents.
"It will let [China] know that we can reach out and touch them should they misbehave," Rounds said.
However, the bomber is not expected to be flying over the Black Hills until 2027, and many of the details of the aircraft, currently being developed by Virginia-based Northrop Grumman, remain unknown or classified.
Rounds was briefed several weeks ago on the project and said that so far it was "on time and on budget."
