1. Idaho became a state on July 3, 1890, but December 31 holds significance as it was on this day in 1863 that President Abraham Lincoln signed into law a bill creating the Idaho Territory. The new territory was created from parts of Washington, Dakota, and Nebraska territories, and included the areas now comprising the state of Montana and the western half of Wyoming.

2. In 1934, on the last day of December, a record-breaking blizzard struck the state. The storm lasted for several days and brought heavy snowfall and high winds, causing widespread damage and disruption to daily life. Many communities were cut off from the outside world and communication lines were down for days. The total snowfall from the storm was measured at up to 40 inches in some areas.

3. December 31, 1901, marked the end of an era when Idaho's notorious outlaw, Harry Orchard, was sentenced to death for the assassination of former Governor Frank Steunenberg. The trial was one of the most sensational in Idaho's history, with Orchard admitting to a series of murders and bombings committed in the name of labor unions.

4. On December 31, 1891, the first issue of the Boise Daily Statesman newspaper was published. The paper, which is still in circulation today under the name of The Idaho Statesman, has chronicled the state's history for over 130 years.

5. December 31, 1975, marked the completion of the Trans-Alaska Pipeline System, which runs from Prudhoe Bay in Alaska to Valdez, Alaska. The pipeline, which is over 800 miles long, was built to transport oil from the North Slope oil fields to the port of Valdez. The project, which took nearly three years to complete and cost over $8 billion, was a major engineering feat and has had a significant impact on the state's economy.