Article continues below advertisementThe Pima County Sheriff's Department remains optimistic in the search for Today show host Savannah Guthrie's 84-year-old mother, Nancy Guthrie. "We have nothing else to go on but the belief that she is here," Sheriff Chris Nanos during a Today show appearance on Wednesday, February 4. "She's present. She's alive, and we want to save her."Article continues below advertisementThe Sheriff Confirmed 'Hundreds' of LeadsSource: @savannahguthrie/InstagramThe Pima Country Sheriff confirmed the department is working through 'hundreds' of 'critical' leads.