Anthony Marnell II was born in Riverside, California and grew up in Las Vegas, Nevada. He attended the University of Southern California School of Architecture. After designing McCarran Airport's A and B Gates, he teamed up with Lud Corrao in 1974 to form Marnell Corrao Associates, the first design-build firm in Southern Nevada. Marnell Corrao built many of Southern Nevada's most iconic hotel-casinos
including the California Hotel, Maxim Hotel, and Sam's Town and Treasure Island, The Mirage, Bellagio, and New York New York as well as the Rio All-Suite Hotel and Casino, and the M Resort Spa Casino.