(Later, the Glen Canyon Dam would be built upriver.) A second Grand Canyon National Monument to the west was proclaimed in 1932. In 1975, that monument and Marble Canyon National Monument, which was established in 1969 and followed the Colorado River northeast from the Grand Canyon to Lees Ferry, were made part of Grand Canyon National Park. In 1979, UNESCO declared the park a World Heritage Site. The 1987 the National Parks Overflights Act found that "Noise associated with aircraft overflights at the Grand Canyon National Park is causing a significant adverse effect on the natural quiet and experience of the park and current aircraft operations at the Grand Canyon National Park have raised serious concerns regarding public safety, including concerns regarding the safety of park users." In 2010, Grand Canyon National Park was honored with its own coin under the America the Beautiful Quarters program. On February 26, 2019, the Grand Canyon National Park commemorated 100 years since its designation as a national park. The Grand Canyon had been part of the National Park Service's Intermountain Region until 2018. Today, the Grand Canyon is a part of Region 8, also known as the Lower Colorado Basin. Legal history timeline 1882 First unsuccessful attempt to establish a Grand Canyon National Park 1893 Designated a "forest reserve" by President Benjamin Harrison (Presidential Proclamation #45) 1908 Established as Grand Canyon National Monument by President Theodore Roosevelt (Presidential Proclamation #794) 1919 Designation of Grand Canyon National Park by an act of Congress on February 26 (40 Stat 1175) 1975 Grand Canyon National Park Enlargement Act an act of Congress on January 3 (88 Stat 2089) (Public Law 93-620) 1979 Designation as a World Heritage Site on October 26 Administrators William Harrison Peters (acting): August 1919 – September 1920 Dewitt L. Raeburn: October 1920 – December 1921 John Roberts White (acting): December 1921 – February 1922 Walter Wilson Crosby: February 1922 – January 1924 George C. Bolton (acting): January 1923 – June 1923 John Ross Eakin: January 1924 – April 1927 Miner Raymond Tillotson: April 1927 – December 1938 James V. Lloyd (acting): December 1938 – February 1939 Harold Child Bryant (acting): February 1939 – January 1940 James V. Lloyd (acting): January 1940 – August 1940 Frank Alvah Kittredge: August 1940 – July 1941 Harold Child Bryant: August 1941 – March 1954 Preston P. Patraw: May 1954 – July 1955 John Sherman McLaughlin: August