United States President Theodore Roosevelt established the Lassen Peak National Monument in 1907. Despite Native population claims that Lassen Peak was full of fire and water and would erupt again, this motion was based on the general belief that Lassen Peak was now extinct, and that its vicinity contained intriguing volcanic phenomena, which could be studied and observed. Once the volcano became active again in 1914, the monument was expanded to establish the Lassen Volcanic National Park on August 9, 1916. The park, in area, can be reached from the California State Route 89 highway.