Time Machine: Bixby ice cave

Cold air flows through nature preserve in Clayton County, even in the summer

This is how the entrance to the ice cave at Bixby State Preserve in Clayton County looked Sept. 9. The cave is closed to the public. (Brian Williams/Elkader)

Cold air still flows out of the ancient ice cave in the Bixby State Preserve near Edgewood in Clayton County.

The 184-acre preserve is kept in its pristine, natural state. It has few amenities — one shelter, built when the area was designated a state park in 1927, and a few picnic areas.

It has no bridges, so if you walk across a stream, you may get your feet wet. Slippery rocks, uneven ground and ancient stone steps pose a challenge.

My husband and I visited at midday Sept. 9. I was determined to photograph the cave. My husband was not thrilled. As I took a photo of the shelter near the path leading to the cave, we met Brian Williams of Elkader, who’d just visited the cave.

I asked how difficult it was to access. He replied it wasn’t difficult, but he wasn’t convinced it was safe for two seniors using canes for balance.

He’d taken a few photos to share with a friend out East and also shared them with us.

Ransom Bixby was a state representative from Delaware County and donated the land for the Bixby State Preserve. (Iowa State Historical Society)

How it came about

The nature preserve came about through the efforts of Ransom James Bixby, a farmer and state legislator, who in 1887 bought three tracts of pristine, geologically interesting land and formed them into a private park that he opened for free for his neighbors to enjoy. He built a log cabin with a stone fireplace for visitors to use.

Capt. A.T. Little of Strawberry Point, a Clayton County pioneer and Civil War veteran, was sure there was lead in the hills around Edgewood. With Bixby’s OK, he got a mineral license, laid wooden rails for a dump cart and began cutting into a limestone bluff.

As the weather turned hot that summer, the interior of his tunnel got colder. The deeper Little and his crew dug, the colder it became. Ice formed on the floor and walls. Little finally up after about 80 feet when frostbite became a threat.

The following summer, the ice-filled cave attracted picnickers, who chopped ice for their ice cream freezers or cooled beer in the cold pools.

Ransom Bixby built a cabin on the land he reserved for recreation in 1887. The land became Bixby State Park. (Gazette archives)

The ice cave was dry in late autumn, but its walls became coated with ice in the spring and early summer.

Park users thought the land should have an official name. In August 1896, attorney B.W. Newberry suggested it be called Bixby Park.

The Bixby family deeded the land and ice cave to the state in 1927, and the State Board of Conservation named it a state park. Prison inmates and workers hired by the Works Progress Administration during the Depression built roads, stone retaining walls, bridges, walks and paths at the park.

The path leading to the Bixby ice cave is shown in July 1964. (Gazette archives)

The ice cave

A story in the July 30, 1916, Cedar Rapids Republican described the park’s geology and then addressed what the readers really wanted to know:

“You want to get cool. ... What a difference down here at the bottom of the hill! Why? There seems to be a cool current coming directly out of the rock; not breezy like those from an electric fan, but steady draughts of cool air flowing from the crevices of the rock, out into the valley.”

“This ice cave is not so well known as the ice cave at Decorah, but it does business in just the same way. … The opening to the ice chest is large enough to admit a man but after a few steps he must get on his hands and knees and his way is blocked after another yard or two. The rock on the sides, above and in front, is thickly coated with ice. And in the far end, the ice is 10 inches thick.”

Jack Thein of Garber cleans out the ice cave in July 1964 at Bixby State Park near Edgewood so people could visit it. The cave entrance has since been closed to the public. (Gazette archives)

Alois F. Kovarik, professor of physics at Yale, explained the ice cave for the Scientific American.

He said the cave was part of a system of interacting fissures and caverns that cut through limestone. By mid-December, moisture near the surface turns to ice and seals it. In the spring thaw, water percolates into the cave and refreezes in the dense, cold air. The air maintains a low temperature well into the summer. Fissures and crevices in the limestone allow the cold air to escape into the summer air.

‘Special habitat’

As the years passed, less state aid was allocated for the park’s upkeep, and local volunteers took over its care in the 1950s. The ice cave had been boarded up for several years before state crews cleaned it out and make it safe for visitors in July 1964.

Six years later, the park was transferred to the Clayton County Conservation Commission. Ten years later, in 1970, the cave entrance had become inaccessible, with visitors able to only see a few feet inside.

Stone steps lead to the entrance of the ice cave in the Bixby State Preserve near Edgewood on Sept. 9. (Brian Williams/Elkader)

In November 1979, the park once again came under state supervision and was dedicated as a state preserve. The Iowa Conservation Commission called it “one of the most special habitats in Iowa, containing a variety of endangered, threatened or otherwise rare plants, including the federally listed monkshood.”

Geologists often came to the area to explore the fragile ecosystems found on the park’s rocky cliffs and around its ice cave. The cave itself is closed to the public.

“In spring and summer, the ice thaws and escapes out of the cliff side,” The Gazette reported in 1987. “It’s been happening for thousands of years, always lagging behind the seasons, never completely thawing.”