Garry Handlen is accused of killing 11-year-old Kathryn-Mary Herbert in 1975 and 12-year-old Monica Jack in 1978.
The Ontario man wore glasses and a jail-issued red sweatsuit when he appeared by video link but said nothing as lawyers in Abbotsford, B.C., set a new date of April 1 to disclose more documents.
The mothers of the girls wiped away tears as they left the courtroom and hugged each other before meeting with prosecutors, but the women declined to comment.
Herbert was reported missing on Sept. 24, 1975, after failing to return home from a friend's house in Abbotsford and her body turned up two months later in an undeveloped area of a First Nations reserve.
Jack was last spotted on May 6, 1978, while riding her bicycle alone along a stretch of highway in Merritt, B.C., but her remains weren't found for another 17 years in a rural area north of the city.
Jack was among the cases assigned to an RCMP task force that investigated the deaths or disappearances of 18 women and girls, mostly along a stretch of Highway 16 in the province's north known as the Highway of Tears.
Mounties announced Handlen's arrest and the charges against him at the beginning of December.
Officers refused to provide specifics of what led to the breakthrough, saying they brought Handlen into custody without incident in Surrey, B.C. He was no longer living in B.C. at the time.