1. In 1955, the 9.2 magnitude earthquake known as the Great Alaska earthquake struck the state on October 3. It is the strongest earthquake ever recorded in North America and caused massive destruction and tsunamis.

2. In 1883, the United States Navy established a coaling station in Unalaska on October 3, which later became a key naval base during World War II.

3. On October 3, 1867, Alaska was formally transferred from Russia to the United States through the Treaty of Cession, which was signed on March 30, 1867.

4. In 1951, the first television station in Alaska, KTVA, began broadcasting on October 3 in Anchorage.

5. In 1917, the first airplane flight in Alaska took place on October 3 when pioneer pilot James "Blackie" Martin flew a Curtis JN-4 biplane from Valdez to Cordova.