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26 Tool Users: The Jensen Pack
Posted on: February 16, 2015
[Photo] David Crothers; Jensen Pack courtesy Ray Brooks
In the summer of 1964, Don Jensen and his Harvard classmate David Roberts endured forty-two days in the Hayes Range on a stormy attempt of Mt. Deborah's friable east ridge. During the retreat, Jensen took two crevasse falls; the second one scarred his face. A year later, when they returned to Alaska to make the first ascent of the Harvard Route on Mt. Huntington, a teammate died. But Jensen's enthusiasm for big mountains remained: he was a climber "for whom no expedition was long enough," Roberts wrote. Restless and solitary, and discomfited by Harvard's clubby milieu, Jensen left Cambridge to complete his undergraduate degree at Fresno State College and earn a PhD in mathematical logic at the University of Southern California. During the summers, he explored the dark granite and frosted notches of the Palisades, sometimes with Joan Vyverberg, whom he met at a Sierra Club event.
Jensen was a practical visionary whose inventiveness informed his climbing, his guiding (at the Palisades School of Mountaineering) and his gear designs. He made tents, bivy sacks, stuff sacks, down jackets, sleeping bags—and a backpack of unusual construction: a lightweight cloth fanny pack sewn to a belfry resembling a SCUBA diver's twin oxygen canisters. An S-shaped nylon septum bisected the main compartment and formed twin vertical tubes that extended to a half-moon-shaped floor that partitioned the main bag from the waist section.
The pack took on its proper form only after Jensen loaded it with gear. Stuffed with a sleeping bag, the waist section acted as the ballast. Soft goods filled the tubes, and hard goods were nested above the vertical baffle. A mere scrim of corduroy separated Jensen's back from the pack's innards, so he placed anything with an edge toward the front. A few leather patches secured crampons, a rope and an ice axe.
In 1970 Jensen's protege Doug Robinson shared the design with the manager of Berkeley's North Face store, Larry Horton. Smitten by such genius, Horton formed Rivendell Mountain Works and began selling the Jensen Pack in 1971. The next year, Chouinard added it to his gear catalog, and word got out: the ergonomic pack allowed climbers and skiers to tackle steep, technical terrain without the awkward sway of an aluminum frame or the roll of a cylindrical sack. Shaped by a brilliant mathematical mind, the Jensen melded with the user's back, but only with careful planning: if packed meticulously, the spineless rig stood tall, its structural pillar formed by the pressure of the contents. Improperly crated, the Jensen puckered and sagged.
Horton sold about a thousand packs during his nine years in business. Neither he nor Jensen ever filed a patent. In the 1970s, Horton attempted to meet the demands of an increasingly sophisticated market by making a bigger, expandable version, but most devotees eventually migrated to internal-frame packs, which, while heavier, were easier and faster to load. Ray Brooks, an erstwhile holdout, says: "I was tired of being the last person out of camp."
In 1973 Don Jensen received a post-doctoral fellowship to Scotland's University of Aberdeen. He was riding his bike to school one November morning when a lorry struck and killed him. Six years later, Horton lost Rivendell as a result of chronic cash flow problems, and he went on to become a doctor of eastern medicine. Don Wittenberger acquired Rivendell's assets in 1981, and today, his sole licensee, Eric Hardee, still makes the Jensen to order—mostly for collectors of vintage gear.
While the Jensen is now rarely seen, vestiges of its blueprint live on in today's form- fitting internal pack designs. And the memory of its creator lingers about the quiet range where, on a midsummer afternoon in 1968, Don Jensen and Joan Vyverberg exchanged wedding vows. The ring he slipped onto her finger bore the silhouette of the Palisade Crest; it was a design he had created himself. Joan slipped its twin onto her husband's finger. Above them, the roaring confluence of the North and South Forks of Big Pine Creek merged into one.
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