- 10,000 years ago is the estimated date that Native American settled the Great Basin area.
- 1,000 years ago Pueblo cultures inhabited the area probably forcing out the Fremont culture.
- 800 years ago human remains were deposited in the natural entrance of the cave.
- 1826-Jedediah Smith crosses Snake Range at Sacramento Pass.
- 1843-1844-John Fremont passes through eastern Nevada.
- 1859- Mormons establish a settlement in Snake Valley.
- 1871-Gold discovered at Osceola.
- 1873-1877-Osceola at its mining peak.
- 1885-Ab Lehman discovers cave in the spring and had installed ladders and stairs throughout the cave by the fall, tours begin. (Discovery date is questionable.)
- 1891-Ab Lehman dies in Salt Lake City, October 11.
- 1892-C. W. Rowland buys Lehman's ranch.
- 1909 -Nevada Forest Service established in the area surrounding the cave.
- 1912-The cave is added to the Forest Service.
- 1920-Clarence Rhodes takes control of the management of the cave.
- 1922- President Harding proclaims Lehman Caves a National Monument. Rhodes continues operation of the cave for the National Forest Service.
- 1933-Lehman Caves National Monument is transferred to the National Park Service jurisdiction on June 10th.
- 1937-Entrance tunnel was started and finished in 1939.
- 1941-Electric lights installed in the cave.
- 1963-New Visitor Center/Administration/Café Building is dedicated.
- 1970-Exit tunnel was completed.
- 1974-Concrete trails installed in cave.
- 1981-Talus Room was deleted from the regular tour route.
- 1986-Great Basin National Park is established and Lehman Caves National Monument is incorporated into the Park on October 27th.
- 2005 - Great Basin Visitor Center in Baker, Nevada, was completed.