Rising tall from the icy waters of the Mississippi River, Tower Rock has stood for centuries as a nautical landmark. And with water levels at their lowest in years, it serves as a destination for local adventurers.

Perry County, Missouri, conservation agent Chris Doran, who heads the Tower Rock Conservation area in Altenburg, Missouri, said when the water line gets low enough, visitors are able to walk across the dry riverbed to reach the massive limestone formation.

"When it's 7.2 feet on the Cape Girardeau side and 1.5 on the Chester (Illinois) side, people can skip from rock to rock to get out there," Doran said.

Doran said this phenomenon occurs every two to three years when the Mississippi starts drawing down.

"The public is more than welcome, but use your best judgment," he said. "If it's icy, it's easy to slip and fall."

Metal debris rests on a receded bank of the Mississippi River at Tower Rock on Friday in Perry County, Missouri.BEN MATTHEWS

Sometimes called the Grand Tower, the site was encountered by the Lewis and Clark expedition on the 23rd day of their voyage up river in 1803. Meriwether Lewis described it in his journal as a "most beautiful and commanding view."

According to the Missouri Department of Conservation, Tower Rock is an erosional remnant formed some 400 million years ago by shifts in the river's channel.

It stands about 60 feet above normal water levels, but with the Mississippi's current levels, the formation is in excess of 100 feet. A small forest of oak, hickory, beech and pine trees thrives at its peak. The surrounding dry, rocky riverbed holds large pools of ice and sometimes displays artifacts from bygone eras, including one massive iron machine that long has been underwater.

Sarah Dippold of Perryville, Missouri, and Josh Engert of Altenburg said they visit the spot often, to listen to the river and enjoy the view.

"To have something like this, essentially in your backyard, it's great," Engert said.

Accompanied by his dog, Rocket, Josh Engert of Altenburg, Missouri, and Sara Dippold of Perryville, Missouri, view the frozen Mississippi River waters surrounding Tower Rock on Friday in Perry County, Missouri.BEN MATTHEWS

Engert said it is a good getaway; to fish for catfish from the stony banks or collect driftwood for a campfire.

Dippold, who works at Grayson's Bar and Grill just up the road, said she brought her family there, four years ago, when it last was accessible.

"The kids love it," she said. "They throw rocks in the water and climb around, just kid stuff."

President Ulysses Grant is credited for sparing the monument from blasting proposed by the U.S. Army Corps of Engineers in the years after the Civil War.

Doran was adamant no climbing is permitted at the site, but the 32-acre nature area does boast hiking trails, a scenic overlook and plenty of opportunity for bird-watching. The area was donated to the state by a Mr. and Mrs. Charles Bussen.

Tower Rock Conservation Area is west of Wittenburg off Route A, south on County Road 460.

Pertinent address:

Tower Rock Conservation Area, Mo.