1872: Yellowstone becomes the nation's first national park.
1890: Yosemite joins in at No. 2.
1906: Antiquities Act allows presidents to reserve historic landmarks and "other objects of historic or scientific interest" on federal lands as national monuments.
1916: Organic Act creates the National Park Service to operate the 14 national parks and 21 national monuments already in existence.
1933: President Franklin Roosevelt transfers national parks and monuments of the War Department and Forest Service to the Park Service, creating a single system of parklands.
1937: Pipestone National Monument created in Pipestone, Minn.
1958: Grand Portage National Monument established on the North Shore.
1965: Voyageurs National Park Association forms to promote creation of the park; founders include writer Sigurd Olson and Gov. Elmer L. Andersen.
1968: St. Croix designated a national scenic riverway.
1972: Lower St. Croix added.
1975: Voyageurs, in the far North Woods, becomes the country's 36th and Minnesota's only national park.
1980: Congress authorizes the North Country National Scenic Trail.
2013: Pinnacles National Park in California becomes the newest national park.
