Prehistory: Rock paintings and skis preserved in bogs show that hunters and trappers used skis at least 5000 years ago.

Early modern period: Skis were in regular use by Scandinavian farmers, hunters and warriors throughout the Middle Ages. By the 18th century, units of the Swedish Army trained and competed on skis.

c. 1850: The cambered ski was invented by woodcarvers in the province of Telemark, Norway. The bow-shape cambered ski arches up toward the center to distribute the weight of the skier more evenly across the length of the ski. Before this, skis had to be thick to glide without bowing downward and sinking in the snow under the skier's weight, concentrated in the middle. If a ski is allowed to bow downward this way, the skier finds himself constantly skiing uphill, out of a hole his own weight has made in the snow. Camber made possible a thinner, lighter ski that did not sink at the middle. The thin, cambered ski floated more easily over soft snow, flexed more easily to absorb the shock of bumps, maneuvered more easily because it was lighter and easier to swing into a turn. The thinner, lighter ski ran faster and maneuvered with better agility than the clumsier sideways skid of the plank-thick older "transportation" skis.

1868: Sondre Norheim demonstrated the Telemark ski, the first with a sidecut that narrowed the ski underfoot while the tip and tail remained wider. In the same way as the camber, the sidecut produced a ski that flexed more easily when tipped on edge, so that in a turn its edge followed the shape of the turn instead of skidding sideways. Norheim and his friends formed a small pioneer group of early skiers who improved the ski as they developed the first dynamic turns in downhill running, from 1850 to 1900.

1882: The first hickory skis produced in Norway. Hickory is so hard and tough that it was difficult to work with traditional hand tools. But with modern carbon-steel tools, Norwegian ski makers began turning out hickory skis. The tough wood made it possible to build a thinner, more flexible ski with good strength, and the hard base was less likely to gouge and scar enough to slow the ski down or cause it to sideslip during a downhill run. Hickory was imported at great expense from Louisiana, and Norwegian immigrants in Wisconsin and Minnesota very quickly figured out that, with easier access to lumber stocks, they could make excellent quality hickory skis more cheaply than their friends back in the old country could. By 1887 several Norwegian skimakers, like the Hemmestveit brothers, had relocated to the U.S.

1893: The first two-layer laminated ski was built by H.M. Christiansen, in Norway. Using a tough hickory or ash base with a lighter body of spruce or basswood made for a lighter, springier ski and reduced the need to carve up thick planks of expensive hardwoods. But the flexible hide glues then in use were not strictly waterproof, so the skis tended to delaminate after a few days' hard use.

1905: An alpine unit of the French Army undertook the first series production of a Telemark-style ski in France, at Briancon.

1928: The segmented steel edge, invented by Rudolph Lettner of Salzburg, Austria, gave skis much better grip on hard snow while still allowing the wood to flex naturally. However, the segments had to be screwed into the ski, and tended to come loose. Worse, edge segments could break in two. In that case, it was difficult or impossible to continue skiing. Skiers sometimes carried spare edge segments, along with a screwdriver, screws and glue, to make field repairs.

1932: the first successful three-layer laminated skis were invented by Bjшrn Ullevoldsaeter in Norway and independently by George Aaland in Seattle. Because they were made with really waterproof casein glues, the skis did not delaminate easily and lasted much longer. When it was found that skis with vertically laminated cores proved lighter, livelier, and stronger, sales took off. The first of these skis were marketed under the Splitkein ("split-cane") label in Norway and as Anderson & Thompson skis in the U.S.

1937: R.E.D. Clark of Cambridge, England, developed the formaldehyde-based adhesive Aerolite to hold airplanes together-- for instance, it was used in the all-wood deHavilland Mosquito bomber. Aerolite phenol glue is still manufactured by Ciba-Geigy.

1944: Cellulix, the first cellulose plastic bottom, made to go on Dynamic skis in France.

1945: The Chance-Vought aircraft company used Aerolite glue to create Metallite, a sandwich of aluminum with a plywood core, for use in airplane skins. Three Chance-Vought engineers, Wayne Pierce, David Richey and Arthur Hunt, used the process to build an aluminum-laminate ski with a wood core. A thousand prototypes were made but the company dropped the project and did not release the patent. It was the first manufactured aluminum ski. It was more easily flexed than a wood ski, less easily broken, scarred or damaged. It did not warp with use.

1946: The Gomme ski was produced by Gomme Ltd in England. A laminated wood core was sandwiched between two top plastic layers and a bottom metal layer. It was the first ski to use three different layered materials. It was good enough to be used by the British Olympic team at St. Moritz in 1948 but eventually went out of manufacture.

1947: Pierce, Richey and Hunt founded TEY Manufacturing to produce the aluminum Alu 60, a two-layer hollow aluminum ski, using the Aerolite bonding process. It had drawbacks: The aluminum base stuck to soft snow and did not hold wax well, and the ski was essentially an undamped spring. The aluminum edges of the bottom plate wore out quickly. It was renamed Truflex in 1948, its second year of production, and TEY shipped 12,000 pairs. But the marketing failed, and the patent was sold to Johnny See-saw. In 1955, the patent ended up with Attenhofer as the Aluflex.

1947: Howard Head, another aircraft engineer, created an aluminum sandwich ski with a lightweight honeycomb core. The aluminum bottom had no steel edges. The ski was too light to track well, and broke easily under bending. It had no edges other than the edges of the bottom sheet. However, it served as a prototype for the later successful Heads.

1948: TEY Tape, a self-adhesive plastic running surface, is invented by the TEY trio. It would adhere to either metal or wood skis. TEY tape did not stick to most snow and it could hold wax. It was sold as part of the Aluflex and also offered through ski shops for application to any ski. Disadvantage: TEY Tape was soft, and relatively easily ripped.

1948: Chris Hoerle of Torrington, Connecticut, created the Chris ski, the first ski with a continuous, low-drag, integral steel edge. This edge was quickly adopted by Head. The Chris ski usually had a TEY tape base but was never brought to market.

1949: Howard Head's plywood-core, pressure-bonded aluminum Head Standard with continuous integral steel edge began its journey toward becoming the most commercially successful early metal ski. It had a plywood core glued under pressure and heat between top and bottom aluminum sheets with plastic sidewalls. The bottom sheet had a continuous full length steel edge. It was the first successful ski made of very different components. The secret to success was a flexible contact cement that allowed the different layers to shear against each other without weakening. Head skis, along with competitors and imitators, supplanted at least half the wood skis by 1960.

1952: The first fiberglass-reinforced plastic ski, the Bud Phillips Ski, was not satisfactory enough to endure. The same applies to both the Holley Ski, created by Dan Holley of Detroit, and the Dynaglass ski by Dale Boison, both introduced in 1955. But these early attempts spread the idea of the possibility of a ski with more liveliness and less vibration than could be achieved with an aluminum ski. Designers saw that a fiberglass ski might be lighter and easier to turn than the best metal skis.

1955: The first polyethylene base is introduced in Austria by Kofler. Kofix proves slippery enough in most snow conditions to eliminate the need for wax. It was easy to repair minor scratches and gouges in it by melting more polyethylene into it. A similar material made by InterMontana in Switzerland was marketed under the brand name P-tex. It was widely adopted by ski factories, and supplanted earlier plastic bases like Cellulix.

1959: The first successful plastic fiberglass ski was invented by Fred Langendorf and Art Molnar, in Montreal, and marketed under the Toni Sailer label. From then on, the concept spread rapidly. By 1968, fiberglass had supplanted both wood and aluminum for use in slalom racing skis and in most recreational skis. Aluminum laminates remained important for all high-speed skis (GS and downhill). Aluminum/fiberglass compound skis proved popular for recreational cruising and for use in deep powder.

1970s: Steady improvement in plastic materials. Prepreg fiberglass construction proves efficient but very expensive. S-glass supplants E-glass in wet lay-ups. Manufacturers mix small quantities of Kevlar, carbon fiber, ceramic fiber and other high-strength materials into fiberglass to help improve strength, resilience, damping, torsion - or simply to improve marketing buzz. Sintered polyethylene begins to supplant extruded polyethylene as a tough, wax-retentive, high-speed base material.

1989: Volant skis, the first commercially manufactured steel ski, introduced by Bucky Kashiwa. The factory failed in 2001 due to high labor costs and production was moved to Austria. Some of the Volant production equipment was bought by David Goode, who uses it to produce a ski made largely of carbon fiber.

1990: Elan and Kneissl build prototypes of deep-sidecut "shaped" skis, escaping from the classic Telemark geometry toward a generation of easy-carving skis.

By the International Skiing History Association