Moving west from the Gulf of Alaska into the interior means cresting a rugged range of mountains that separate two great drainage systems. One system drains from their crest back to the Gulf. The other drains north through the Yukon River System to the Bering Sea. The generals who routed the Alaska Highway through Alaska blithely dispatched the 97th to crest the Continental Divide through the notch through the towering mountains known as Mentasta Pass.
The original trail over Mentasta–Abercrombie’s
The Pass lies just four miles east of Mentasta Lake, at a much higher elevation. Cresting there would be a trick.
Going east from the lake shore, a deep canyon penetrates the mountains. It ends abruptly at a towering wall just south of the Pass. Fifty years earlier Abercrombie had carved a pack trail out of the north wall of the canyon, angling up and then along the cliffside to emerge at the higher elevation of the pass. Unfortunately, his trail, long gone, still showed on the generals’ maps and, therefore, lived in their imagination.
The mountains that bounded the canyon had formed under glaciers. Part of a terminal moraine, the north wall of the canyon consisted of debris accumulated over thousands of years as the glacier moved, abrading and grinding the rock beneath it. The front edge of the ice slowly pushed the debris along and, when it melted, dumped it in a monster heap. Cresting would be easy, getting to the notch was another matter.
The glaciers had left a canyon whose walls consisted, not of solid rock, but of deep, down-pointing folds of finely ground rock. Men carve a trail or a road out of a cliff wall by creating a ledge. The glacial debris didn’t lend itself to ledges. Ledges tend to disappear under debris sliding down from above. And, more important, the outer edges of ledges, the ones suspended in thin air out over the depth of the canyon, tend to crumble and fall away.
Heath Twichell described the challenge that faced the catskinners of the 97th.
“While working on the precipitous terminal moraine…the lead bulldozers repeatedly slipped off the narrow trail and ‘threw a track.’” Reinstalling a tread back onto its drive sprocket, relatively routine on flat ground, became something very different in Mentasta Pass. “…doing it on a 23-ton machine that was teetering on the edge of a crumbling slope of glacial debris called for great skill and calm nerves. Eventually the 97th’s inexperienced operators became masters at such on-the-spot repairs…”
