Casida was last seen leaving her Reno, Nevada residence on February 14, 2006. She was driving her white 1991 Mazda pickup truck with the Nevada license plate number 920 NRH at the time of her disappearance. She has never been heard from again. On March 5, her truck was found abandoned at the 205 Pumpernickel Valley exit ramp off Interstate 80 near Winnemucca, Nevada. Curiously, this is the same exit where Patrick Carnes's truck was found after he disappeared in 2012. He was never located. Authorities have no evidence that the two cases are connected, however.

Casida left a note behind at home, saying she was depressed over her life and the state of her marriage. She has family members residing in Oregon. There has been no activity on her bank accounts since her disappearance. Her case remains unsolved.