His father, Walter Orr Roberts, was an astronomer and scientist who headed the Harvard College Observatory in nearby Boulder; his mother, Janet Naomi Smock Roberts, was elected to its city council.
[2] Roberts attended Boulder High School, before studying mathematics at Harvard University, graduating in 1965.
He was a member of and former president of the Harvard Mountaineering Club where he led exploratory first ascents of many peaks in Alaska.
[1] In thirteen seasons spent in the Alaskan wilderness, Roberts was well known for many first ascents, including the Wickersham Wall on Denali, the west rib of Mount Huntington, climbing in the Western Brooks Range and the Kichatna Spires, and on the east face of Mount Dickey.
His final book, Into the Great Emptiness: Peril and Survival on the Greenland Ice Cap, is scheduled to be released in mid-2022, one year after his death.