Chimney Rock is a rare sight

'Walk gently," says a state sign near the tall sandstone spire known as Chimney Rock near Hastings.

The rare rock pillar, standing nearly 30 feet tall, is the centerpiece of Dakota County's newest Scientific and Natural Area.

From the fragile looks of the weathered and cracked pinnacle, gentle steps and no rock climbing would be warranted to keep the ancient natural monument upright. It's the last of three wind- and water-sculpted rock spires still standing in Dakota County, said Al Singer, county land conservation manager.

The sandy tower, which rises from a base about 10 feet across, is the star attraction in a 76-acre hilly and wooded tract bought for $550,000 last year by the state Department of Natural Resources (DNR) and Dakota County. The county chipped in $80,000 to keep the property undeveloped forever. The money came from a county bond issue voters approved in 2002 to preserve farm and natural areas.

Chimney Rock, for decades near the top of a DNR list of unusual areas needing protection, served as a landmark for settlers moving into the area in the 1800s. The pillar, with a limestone cap, began forming about 14,000 years ago, when the last glacier receded from northern Dakota County, Singer said. The shaft was eroded from a sandstone mesa, mostly by glacier melt water.

The natural area, which also shelters four rare plants, got its first official cleanup a week ago when four bags of beer cans and trash were collected by the Hastings Environmental Protectors. The group also held a bird hike in the area, said birder and group leader Kevin Smith.

"It's a good thing to share a treasure like that," said Smith, who lives a few miles away in Hastings. He said some of the 16 people who visited the rock had never seen it before. They also spotted a red-tailed hawk, nuthatches, juncos, a lot of deer tracks and some huge red oaks in the hillside forests, he said.

Just up the oak-covered hill from Chimney Rock squats another sandstone monolith, eroded by elements or people to 10 to 15 feet in height. It stretches about 50 feet and bears countless initials carved in its soft stone.

Why is Chimney Rock important?

"Anybody who has an interest in nature may be interested in the protection of these unique features, to preserve them so the public can enjoy them and scientists can learn from them," said Peggy Booth, supervisor of the DNR's Scientific and Natural Areas (SNA) program. She said some rare plants also have genetic makeup that scientists want to study before they disappear.

The DNR hopes to get more local stewards involved in monitoring the state's 155 Scientific and Natural Areas, Booth said. A DNR official at the cleanup asked the Hastings group to consider being a steward of Chimney Rock, which is located about 7 miles southwest of the city in Marshan Township. Smith said the group will visit a few times a year and let the state know if anything is amiss or if state signs are damaged.

The DNR also is encouraging more Scientific and Natural Area events, such as nature walks, cleanups or school field trips.

"We don't want hordes of people trampling native plants," agency spokesman Harland Hiemstra said, "but we are trying to find a balance of making the public more aware of the unique things they have."

Chimney Rock was described in 1905 as "the most picturesque and perfect example of columnar rock weathering in Minnesota," notes the Dakota County Historical Society. The natural area also has several scarce habitats, such as oak savannah, and four rare plants, including kittentails and beach heather.

Dakota County used to have two other sandstone spires. Castle Rock, in the township that bears its name south of Farmington, has collapsed. Lone Rock, in Empire Township, is worn down but still has some height, Singer said.

Lone Rock, in UMore Park south of Rosemount, was noted by explorer Zebulon Pike in the early 1800s, Singer said.

Jim Adams • 952-746-3283