1. On April 27, 1962, the Teton Dam in southeastern Idaho was authorized by Congress. The dam was completed in 1976, but only lasted 6 years before it failed, causing a catastrophic flood that killed 11 people and caused over $1 billion in damage.

2. Idaho's state tree, the western white pine, was designated as such on April 27, 1935.

3. On April 27, 1922, the Idaho Legislature passed a bill allowing women to serve on juries, becoming the 18th state in the nation to do so.

4. Idaho's first ever state capitol building was completed on April 27, 1885. The building, located in Boise, served as the state capitol until 1905 and now serves as the Idaho State Historical Museum.

5. On April 27, 1863, a treaty was signed between the United States government and the Nez Perce tribe that ceded over 6 million acres of land to the U.S. government in exchange for a reservation. However, the treaty was not upheld by the government, leading to the Nez Perce War of 1877.