Today’s story has its roots—so to speak—in the subtropics that covered most of North Dakota 60-million years ago. It was the Paleocene Epoch, during which time palm trees, redwood trees, sycamores, magnolia and bald cypress trees provided habitat for turtles, crocodiles, champsosaurs, alligators and many other exotic animals.
Fast-forward to modern-day North Dakota. For several years, a sugar beet farmer living near Williston had been escalating a hobby into a consuming passion. In 1981, the Bismarck Tribune reported, “[Sixty-five year old Clarence] Johnsrud had been a farmer all his life, but had since 1978 switched from working the land to working in the land. About 16 miles southwest of Williston, Johnsrud walked down the road to his neighbors’ hill every morning and began digging. The neighbors, the Gibbins, claimed, ‘This hill is Clarence’s.’ In three years, Johnsrud had found 34 varieties of fossilized plant life [including a] petrified redwood tree.”

Six years after that story ran, a road construction crew was rebuilding a rural road running between Williston and Fort Buford on the old Lewis and Clark trail. As bulldozers dug into what’s known as the Sentinel Butte Formation, they excavated a substantial deposit of hard, cream-colored mudstone. When fossils were discovered, someone contacted Johnsrud.

Johnsrud drove over to have a look and quickly convinced the road-construction supervisor to hold up and allow him to haul away the mudstone so it wouldn’t get reburied beneath the new road in what would thereafter be known as the Trenton Hill fossil site.

For the next several days Johnsrud used a farm loader and truck to deposit several tons of rocks into his barn. Hand-splitting the rocks with a hammer and chisel, his efforts soon began yielding what would become some of the finest plant fossil specimens in the world.

Some 13 years later, Johnsrud estimated he had cracked opened some twenty tons of stone, exposing several hundred exquisite fossils. Not one to keep his discoveries to himself, Johnsrud donated some of his pieces to UND-Grand Forks and UND-Williston and also to Minot State. He also donated several specimens to the Denver Museum of Natural History and the Florida Natural History Museum.

It was about this time in 2000 that Johnsrud donated the bulk of his collection to the North Dakota Geological Survey State Fossil Collection at the North Dakota Heritage Center. He and his family also included a gift of $200,000 to create a permanent exhibit for the fossils and to help renovate the Geological Survey’s paleontology lab at the Center. The North Dakota Geological Survey thereafter named the modernized facility the Johnsrud Paleontology Laboratory. Many of Johnsrud’s beautiful plant fossils are on exhibit at the Heritage Center and will become part of the new Corridor of Time fossil exhibit, which will open this fall.

Written by Merry Helm

Source:
The Bismarck Tribune. June 15, 1981: 3.
Hoganson, John. North Dakota Geolological Survey Newsletter. Vol 27, #1. Summer 2000: 7-10.

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