HAPPY BIRTHDAY IDAHO. Idaho became the 43rd state on July 3rd 1890. Therefore, to celebrate the birth of the best state in the union I decided to hide a couple of caches in the honor of the people of the state. So let off some fireworks a day early and celebrate on the 3rd. There isn't any laws that say we can't have a party for 2 days in a row. so, party on the 3rd and then again on the 4th for independance day.