In 1925 , Indian River County was created out of the northern part of St. Lucie County , while Martin County was created from a small part of southeastern St. Lucie County and the northern part of Palm Beach County during that same year .
In 1925 , Indian River County was created out of the northern part of St Lucie County , while northern Martin County was created from a small part of southeastern St. Lucie County and the northern part of Palm Beach County .