Scott,
Below is your answer......Taken from the Gaming Chips column of the Las Vegas Review Journal March 25th, 2001. Andy - Las Vegas

TRIVIA TIME: Nevada legalized gambling in the state 70 years ago, on March 19, 1931. The law gave cities and counties sole power to collect taxes and issue gaming licenses. What gambling establishment received the first such license in Clark County?

TRIVIA ANSWER: The Northern Club received Clark County's first gaming license shortly after the Legislature legalized gambling again. The club was on the south side of Fremont Street, east of the Golden Gate's current location.