• Explore and Discover One of the Last Frontiers in the World ...

    Jewel Cave

    National Monument South Dakota

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  • Caution - Roadwork on Highway 16 - Expect Delays

    Construction projects both along highway 16 and the Jewel Cave parking lot are planned during this summer season. The visitor center will be open daily, 8:00 a.m. – 5:30 p.m. Tours are scheduled throughout the day. No reservations for cave tours. More »

Public Involvement

South Dakota Department of Transportation
Notice of Approval of Environmental Assessment
for Public Availability

US Highway 16
SDDOT Project No. NH 0016(72)11, PCN 022E
Custer County, SD

The Federal Highway Administration has approved the above project’s Environmental Assessment and Section 4(f) Evaluation for public availability. The document discusses the Environmental Assessment and Section 4(f) Evaluation for the segment of US16 from 1 mile West of Jewel Cave National Monument to 0.5 miles East of Jewel Cave National Monument.

Copies of the Environmental Assessment are available for review at the following offices:

SD Department of Transportation
Environmental Office (Room 312)
700 E. Broadway Ave.
Pierre, SD 57501

SD Department of Transportation
Custer Area Office
PO Box 431
Custer, SD 57730-0431

The document is also available for download from


For further information regarding this project, contact Tom Lehmkuhl, SDDOT at (605) 773-3180. Comments on this Environmental Assessment should be submitted by August 28, 2013 to:

Tom Lehmkuhl, Environmental Engineer
South Dakota Department of Transportation
700 East Broadway Avenue
Pierre, SD 57501-2586

Dated in Pierre, South Dakota this 19th day of July, 2013.
(Published twice at the total approximate cost of $____.___)

Did You Know?

Beautiful gypsum flowers in Jewel Cave/NPS file photo

When Jewel Cave was established as a National Monument in 1908, it was thought to be a small but pretty cave. It wasn’t until 1959 that explorers began to realize that Jewel Cave may be one of the longest caves in the world.