Prosecutors say Ehlers, of Moab, dislodged a piece of sandstone with a three-toed dinosaur track from the Hell's Revenge jeep trail in the Sand Flats Recreation Area near Moab in eastern Utah.
The print is from the Jurassic Period and up to 190 million years old, Bureau of Land Management paleontologists have said. Christensen said the footprint is particularly priceless because no bones or other fossils from the dinosaurs who left it have been discovered. The footprint is one of 26 in the area, she said, and is the only evidence paleontologists have to study the dinosaurs.
Christensen said the restitution will go to pay for search efforts. Officials have not been able to find the stone since it was removed Feb. 17. Prosecutors believe Ehlers later dumped the footprint into the Colorado River about 32 miles northeast of Moab.
Divers searched the river for a day in March but didn't recover the fossil due to limited visibility, according to authorities.
Ehlers' attorney, Tara Isaacson, told a judge Wednesday that her client did not take the footprint for monetary gain, but she never said why he did it.
"He didn't dig it out," Isaacson said. "He lifted the rock and put it in his vehicle ... He made a terrible decision in removing that track and ultimately disposing of it."
Christensen said investigators were able to look at video footage from the day of Feb. 17, and saw Ehler's truck leave the area. They interviewed the man, the prosecutor said, who first denied taking the footprint.
"He clearly became anxious about that," Christensen said of the investigation. "And that's what led him to throw the artifact ... he threw it off the bridge and into the river."
A four-day trial had been scheduled to start Monday.
Ehlers, who works in construction, had faced up to 45 years in prison on charges of theft of government property, damage to government property, destroying evidence and removal of paleontological resources. The latter charge stems from a federal law passed in 2009 to protect paleontological artifacts and carries a maximum penalty of 20 years.
All charges but the removal of paleontological resources count were dismissed Wednesday.
Christensen said Ehlers' conviction should send a message to anyone tempted to do something similar.
"You wouldn't go into an art museum and take a piece of art because you felt like it," she said. "This is the same thing. You are stealing our history, the history of American people, the history of our country. The history of prehistoric time has been stolen. So, the message is, don't do it, leave it there for other people to enjoy, and if you make the bad judgment to do it, you will be punished."