I'm thinking that you mean Moe Dalitz, but he was a gangster--during Prohibition, he ran the Mayfield Road Gang that shipped oceans of booze across Lake Erie. Wilbur Clark also is a "pioneer" of Vegas, though many historians think he just fronted for the Mob. Senator Pat McCarren also is sometimes called "father" of Vegas.
Assuming one of the above is who you had in mind:
What was the first Vegas hotel that Bugsy Siegel muscled into? (Good try on El Rancho--he tried to muscle in there but was rebuffed. The hotel I have in mind was his next move.)