BIG TIMBER, Mont. -

A truck driver denies he hit and killed and Alaska man on Interstate 90 near Big Timber last fall.

David Welk appeared before district Judge Brenda Gilbert Friday morning and pleaded not guilty. Police returned Welk to Montana this week, after arresting him in Iowa.

Welk is charged with knowing or reasonably knowing he was in an accident that resulted in serious bodily injury and failed to remain at the scene. The second charge is for knowing or reasonably knowing he was involved in an accident with a deceased person and failed to remain at the scene. However, prosecutors tell us Welk can only be convicted of one of those charges.

Welk is accused of hitting 81-year-old Elgie Bedford as the man was walking in the westbound lanes of I-90 near Big Timber last September.

Court documents indicate Welk and another man were traveling through that area when the other man felt a collision. He told investigators Welk began yelling he had hit someone so the pair turned around to see if they could find what they hit.

According to court records, Welk and his co-driver stopped near the site of the accident. Welk checked the road and reportedly told his partner they were only clothes and a duffle bag, but Welk told troopers and his boss two different stories.

"Through the hard work of the highway patrol, I think we've finally found the original driver," says Sweetgrass County Attorney Patrick Dringman.

Dringman tells us he was a little surprised they were able to track down Welk.

He originally charged a Washington woman with leaving the scene of the crash and tampering with evidence after she and her father allegedly hit Bedford's body and washed remains off their truck at a car wash. After further investigation, Dringman set his sights on Welk.

"I think the state has a good case," says Dringman.

Welk's defense attorney declined to comment on the case. Welk is being held on $250,000 bond at the Gallatin County Detention Center.