▁the ▁service ▁was ▁given ▁a ▁renew ed ▁focus ▁on ▁research ▁and ▁development . ▁M uro c ▁Field ▁drew ▁attention , ▁because ▁the ▁nearby ▁dry ▁lake ▁was ▁so ▁flat ▁( Ar n old ▁described ▁it ▁as ▁" level ▁as ▁a ▁bill i ard ▁table ") ▁that ▁it ▁could ▁serve ▁as ▁a ▁giant ▁run way , ▁ideal ▁for ▁flight ▁testing . ▁ ▁Over ▁US $ 1 2 0 ▁million ▁was ▁spent ▁to ▁develop ▁the ▁base ▁in ▁the ▁ 1 9 4 0 s ▁and ▁expand ▁it ▁to ▁. ▁The ▁base ' s ▁main ▁ ▁run way ▁was ▁completed ▁in ▁a ▁single ▁pour ▁of ▁concrete . ▁ ▁World ▁War ▁II ▁ ▁On ▁the ▁afternoon ▁of ▁ 7 ▁December ▁ 1 9 4 1 , ▁the ▁ 4 1 st ▁Bomb ard ment ▁Group ▁and ▁the ▁ 6 th ▁Re con na issance ▁Squadron ▁moved ▁to ▁M uro c ▁from ▁Davis - Month an ▁Army ▁Air field , ▁Arizona , ▁with ▁a ▁collection ▁of ▁B - 1 8 ▁Bol os , ▁B - 2 5 ▁Mitch ells , ▁and ▁an ▁A - 2 9 ▁Hudson . ▁ ▁On ▁Christmas ▁E ve , ▁the ▁ 3 0 th ▁Bomb ard ment ▁Group ▁and ▁the ▁ 2 d ▁Re con na issance ▁Squadron ▁arrived ▁from ▁New ▁Orleans ▁Army ▁Air base , ▁Louisiana , ▁for ▁crew ▁training . ▁On ▁ 2 3 ▁July ▁ 1 9 4 2 , ▁the ▁M uro c ▁Bomb ing ▁and ▁G unn ery ▁Range , ▁M uro c ▁Lake , ▁California , ▁was ▁designated