Story highlights Bones were found in the car, authorities say

Cheryl Miller and Pamela Jackson disappeared in 1971 en route to a party

A car was found Monday in a creek, a report says

A jail inmate was once charged in the case, but the charges were dropped

They were 17-year-old high school students driving to a party at a gravel pit. Perhaps they took a wrong turn; perhaps there was foul play. For 42 years, authorities have had no idea how Cheryl Miller and Pamela Jackson disappeared.

Now there may finally be answers.

A car that appears to be theirs was spotted in a creek just half a mile from the girls' intended destination near Beresford, South Dakota, reported CNN affiliate KTIV-TV in Sioux City, Iowa. The license plate and hubcap match those of the car they were in when they vanished in 1971.

Authorities in South Dakota said Tuesday that skeletal remains were recovered from the scene.

South Dakota Attorney General Marty Jackley and Union County Sheriff Dan Limoges also said the vehicle, discovered in an embankment in Brule Creek, was processed and other items that potentially are evidence were discovered.

A car that appears to be Cheryl Miller and Pamela Jackson's was spotted in a creek just half a mile from the girls' intended 1971 destination near Beresford, South Dakota, reported CNN affiliate KTIV-TV.

The timing is especially poignant. Jackson's father died last week at the age of 102. His funeral was Saturday. The car was found Monday.

It's caked in mud, which must be peeled off layer by layer, KTIV reported.

Dry weather had depleted the creek of enough water that it became easy to see the car, the station said.

A fisherman spotted the 1960 Studebaker Lark, said CNN affiliate KSFY-TV in Sioux Falls, South Dakota.

Removing the car from the creek could take days, KSFY said.

"The case has been reopened multiple times over the decades, including in 2004, when the state's newly formed cold case unit searched a farm in rural Union County, two miles from the gravel pit," KSFY reported.

Six years ago, state prison inmate David Lykken was charged in the case. But the charges were later dropped after a confession he gave turned out to be false, KSFY said.

Last week, authorities found two cars, with human remains inside, at the bottom of an Oklahoma lake.

Investigators said one car may have belonged to a teenager who disappeared with two friends in 1970. The other might be linked to the disappearance of a man in the 1960s.