On June 8, 1906, President Theodore Roosevelt signed into law the Antiquities Act. In its initial conceptual form was to protect to prevent looting of archaeological sites. It was later revised to include historical sites and also landmarks of scientific importance. Once a site designated it became a National Monument.
Louis Barrett of the Lassen National Forest was concerned about two sites within its jurisdiction that could be developed into commercial tourist attractions—Cinder Cone and Lassen Peak. In the spring of 1906, in an effort to ward off future claimants he started a petition to make Cinder Cone and Lassen Peak into a national park. This did not gain the traction Barrett desired.
For Barrett, the passage of the Antiquities Act came at an opportune moment. It provided him with another way to protect the features of Cinder Cone and Lassen Peak. He surmised the opposition to make them National Monuments would be minimal, for less than 10,000 acres of public land would be withdrawn, versus 100,000 acres for a Lassen Peak National Park. At the same time, the national monument designation would not interfere with the establishment of a national park at a later date.
In early 1907, Barrett submitted the necessary paperwork for the creation of two national monuments—Cinder Cone and Lassen Peak. U.S. Secretary of Interior James Garfield liked the concept of two smaller national monuments better than a proposed national park. Of course, the maintenance of national monuments would be nominal compared to a national park. With no opposition, proclamations were prepared and submitted to President Roosevelt. On May 6, 1907, Roosevelt established the Cinder Cone National Monument (5,120 acres) and Lassen Peak National Monument (1,280 acres). They became the six and seventh national monuments established under the Antiquities Act.
The movement, however, to create a Lassen Peak National Park did not fade away. One of the biggest obstacles was it was not well known, even in a regional sense. That all changed on May 30, 1914, when Lassen Peak erupted, and with it nation wide publicity. On August 9, 1916, Lassen County lost its only national monument, when it was incorporated into the newly created Lassen Volcanic National Park.