1 BINDING: Voilé Split Decision Plate Bindings $90 The genius of a split snowboard like Voilé's isn't the split—you can split any board with a simple $130 kit—but rather the plate that provides a platform for free-heeled, ski-style ascents and then rotates to serve as a solid anchor for your snowboard descent. A removable cotter pin holds the plate securely in either mode. Although you can attach any binding to the plate, multiday expeditions require gear worthy of big mountains. We used Voilé's hard-plate bindings; at only 28 ounces per pair, the stainless steel design will fit most plastic ski- or snowboard-mountaineering boots, which means you don't have to stop when the going gets steep to change into boots that accept crampons. The Downside? Those cotter pins can be tough to keep track of when you're cold and tired; they should be attached with a wire leash. Carry spares or you'll be walking.

2 BOOT: Garmont GSM $380 Although the Garmont GSM is technically a ski-mountaineering boot and not a snowboard-mountaineering boot, the differences are largely semantic—the plastic boots work brilliantly for knuckle dragging. There's just enough flex for smoothing out chunky, frozen corn without being too soft for belly-drag carves. As for the ascents, the 6-pound, 10-ounce boots have a tacky Vibram sole with enough rocker to make walking and climbing over rocks comfortable. Three buckles and a Velcro strap around the cuff allow you to finesse the fit, while the removable liners make for great camp shoes. The Downside? Like any AT boot, the GSM has cuffs that come up a little high and make sidestepping in crampons somewhat awkward. But this isn't a pure mountaineering boot—a fact you'll appreciate when you're scribing perfect half-rounds for 2,000 feet.

3 BOARD:Voilé Split 173 $665 There's no getting around it: The idea of entrusting your big-mountain descent to a snowboard with a crack running down the middle is damn disconcerting. But never fear. Once the bindings are slotted into place, you essentially have two I-beams running across the board. Most sizes feature an extended wood core that is comfortably stiff and holds firmly on hardpack. During ascents, a single-setting heel lifter keeps your calves from combusting, while the girth of the two-edged "skis" makes walking through deep powder a breeze. It takes a few sessions to get the hang of putting the board back together again after skiing up, but it's not hard. The Downside? The two plastic hooks that keep the nose and tail joined have a tendency to work themselves loose. Yikes.

1 APPROACH SKIS: K2 Ascent $300 Split boards may seem like the logical choice for expedition skiing because instead of carrying the board uphill, you ski the board uphill. Approach skis, however, have their advantages. K2's 108-centimeter Ascents weigh only 24 ounces each—hardly noticeable when strapped to your pack for the ride down. And since you don't have to remove the skins or fumble to put your board back together, the approach skis make for a faster transition when you get to the top. (Which, of course, means dibs on the best untracked lines.) The Downside? Problems arise when your trip demands heavy packs loaded with gear for glacier travel and overnights above 10,000 feet. Our tester was burdened with a 10-pound snowboard strapped to his already portly pack. And since the skis don't distribute weight as widely as their split-board cousins, you're likely to find yourself sinking in soft snow. In powder, you'll flounder and be eaten by ravens. Furthermore, the lack of a heel lifter is inexcusable and makes climbing the steeps painful. A wider, longer ski for bigger riders and deeper snow would be a welcome addition.

2 BOOTS:K2 Sidewinder $300If you use approach skis on your climb, you'll need crampon-compatible boots. Although K2 makes a 12-point crampon that snaps onto Clicker boots, the setup requires a leap of faith not everyone will feel comfortable making. They seemed to work fine on Rainier's Ingraham Glacier, but our tester never had total confidence. Crossing scree slopes, scrambling through boulder fields, and front-pointing up seracs in squishy snowboard boots isn't exactly ideal either. Luckily—although it was a little late for our June trip—K2 just introduced the Sidewinder, a hybrid backcountry snowboarding boot that accepts standard crampons and has a rigid sole for kicking steps, but still snaps onto Ascent skis and Clicker boards. The Sidewinder combines a synthetic-leather-and-nylon upper with a stiff, plastic back for support when carving turns. The boots also adjust from touring to riding modes. The Downside? At 9 pounds, 12 ounces per pair, you need quads like Hermann Maier.

BOARD (not shown):K2 Eldorado $419This 7.5-pound snowboard has a Superlight wood core that makes the all-mountain plank 22 percent lighter than the company's standard issue. Result: less burden on your back. The board's sidecut graduates from elliptical at the nose (which helps get your turns under way) to radial at the tail for sturdy carving. The fat, spoonlike nose keeps the board above the powder, and a grommet in the tail will hold a carabiner should you need to rappel. The Downside? It's light, but you still have to carry it. —T.N.