( CNN ) -- South Dakota investigators have put to rest a 42-year-old cold case about two missing 17-year-old girls , declaring they died in a car accident that ended in a creek at night in 1971 , with no signs of foul play . Cheryl Miller and Pamela Jackson were high school students when they disappeared May 29 , 1971 , while driving to a party at a gravel pit . It took 42 years for their car to be discovered -- last September -- just a half-mile from the girls ' intended destination near Beresford , South Dakota . Last year 's weather -- a wet spring followed by strong creek currents and then a drought -- caused the car to become visible and recovered , caked in mud , authorities said . Subsequent DNA , forensic and anthropological analyses confirmed the identities of the two sets of remains found in the car and also concluded that the girls ' deaths were accidental , South Dakota Attorney General Marty Jackley told reporters Tuesday . Their 1960 Studebaker Lark 's ignition and headlights were turned on , and the transmission was in the top , or third , gear , Jackley said . Their clothing contained bones and remnants of shoes were found , and no evidence of alcohol was found in the car , he said . `` No evidence indicates that there was foul play . This would appear to indicate an accident , '' Jackley said . The announcement `` brings a closure '' and gives the families `` some answers , '' Jackley said . The families will now be able to collect the two girls ' remains , he added . The attorney general said investigators do n't know what caused the accident , but he noted that one car tire was damaged , though authorities do n't know whether a blowout caused that . He also cited how the tread on the tires were low . Jackley showed reporters some of the personal belongings found in the car , including two classmate notes and Miller 's purse . Kay Brock , Jackson 's sister , told CNN affiliate KSFY that the DNA confirmation finally ended the long uncertainty . `` I 'm relieved to have no foul play , '' Brock told the station . `` It 's nice to have a permanent answer after 42 years . '' Taken : The coldest case ever solved . Police get break in missing girls ' cold case from 1975 . Arrest in 40-year-old murder case . CNN 's Josh Levs contributed to this report .
Authorities confirm the identities of two sets of remains found last year in a car . Investigators also conclude the two girls died in a car accident , with no signs of foul play . Cheryl Miller and Pamela Jackson disappeared in 1971 . Their remains were found last September in their mud-caked car in a creek .