Smoke first billowed from the stone bulwark of Grey Cloud Lime Kiln at least a dozen years before there was a state called Minnesota, when the wail of steamboat whistles echoed off the nearby Mississippi River bluffs.

The kiln labored through the Civil War, burned on as the area was transformed from wilderness to farmland and kept on going right into the 20th century.

By 1902, the kiln — believed to have been built in 1846 to process limestone and listed on the National Register of Historic Places — closed and the fires stopped.

Yet it remained a landmark, weathering more than 160 years of blizzards, thunderstorms and floods.

Then came June 2014.

With near-record rainfall, and floodwaters from the Mississippi's Grey Cloud Island channel lapping at its foundation, three walls of the kiln toppled in a heap of rubble and limestone powder that was still inside from 1902.

Now the future of the structure — believed to be the first of Minnesota's National Register sites destroyed by nature — as a protected piece of history is in question.

'Pride and joy'

"It's a tragedy," said Marge Schmaltz, 94, who has lived on the channel-front property where the kiln is located since 1961 and who plans to bequeath her entire property to the state. "I think it just came down to old age and all that water seeping in."

For Schmaltz and her late husband, Otto, the kiln was an old friend, a big part of why they were drawn to build a house at the site in south Cottage Grove that is separated by the river channel from Grey Cloud Island.

Otto Schmaltz built walking paths around the kiln, along with a rock cairn for displaying the plaque describing its history. He also installed two spotlights to play on it at night.

"That was his pride and joy," Marge Schmaltz said.

For Kyle Dippel, whose family had a house next door and who moved back to the area 20 years ago, the loss is also personal.

"You get these feelings for landmarks you grew up with as a child," he said. "You just always want them to be around."

Dippel said that he and his cousin loved to play at the kiln but that they weren't allowed by their parents to go through one of the three arched portals for fear the kiln might collapse. The portals were capped by keystones, and the kiln was built of massive, square-hewn limestone boulders.

Dippel marvels at the 20-foot-square, 35-foot-tall structure, built by unknown pioneers without the aid of engineers or architects.

"How the heck did they do that?" Dippel said. "It's almost like the way they built the pyramids — only a small one."

How it worked

The kiln is essentially a massive chimney, said Herb Reckinger, head of the South Washington Heritage Society. Fueled by an ample supply of wood, it was used to reduce limestone from nearby bluffs or quarries to a powder form called quicklime that was used in fertilizer, plaster and mortar.

The timber was loaded at the bottom of the kiln through the three portals, Reckinger said.

The kiln, brick-lined with walls 3 to 4 feet thick, was built on a slope. Limestone was hauled in by horse and wagon, then brought by wheelbarrow on a wooden trestle to the top, where it was dumped in. Remnants of the timbers are still visible.

"It would burn for days," Reckinger said. "Eventually, all that loose limestone would become powder."

The quicklime was then put in barrels, the bulk of it likely destined for farms, he said. Lime was essential in correcting acidity in soil that resulted from farming, and having a ready source was important to the growth of the local economy, Reckinger said.

Because of that, and because the kiln is one of the last remnants of early industry in Minnesota, it was added to the National Register in 1978.

Status is in doubt

The kiln's status on the register, which gives it certain protections, will now have to be re-evaluated.

"In order for a property to be considered historically significant, it can't just be important — it also has to have historic integrity," said Denis Gardner, the state's National Register supervisor. "That's the rub with this."

Among the questions to be answered is whether the kiln is still recognizable enough to convey that sense of what made it important. Given the extent of destruction, that seems doubtful, Gardner said.

The kiln might be the first site on the register lost to a disaster.

"I don't think we've had anything as bad as this, that's just collapsed," he said.

Several historic homes and buildings, including the Nicollet County Courthouse, were heavily damaged in a 1998 tornado that tore across St. Peter, Minn., but they were rehabilitated, Gardner said. In fact, the town's commercial district became a National Register historic district after the tornado.

There is a chance, however, that the kiln's official historic significance could be retained, but redefined as an archaeological site.

"The question we have to look at is, 'Even though it's collapsed, is there still enough information there to reveal history?' " Gardner said. "The short story is, it's going to have to be reassessed."