Field Test: Stone Glacier Sky 5900 w/XCurve Frame

Updated: August 3, 2024 BY Jace Bauserman

I’m a bit of a backpack fanatic and I’ve tested piles of them over the years. One of the things I’ve learned is there is no one-size-fits-all solution. Each adventure — from the whitetail woods of the Midwest to the elk-rich Rockies — requires a particular pack. Trek in for a 10-day elk hunt with a 1,500-cubic-inch pack with limited adjustability and a design not engineered to haul a load, and you’ll have serious problems. Climb into a gnarled cottonwood with a 5,000-cubic-inch monster, and space issues along with problematic access to right-now gear arise. You get the idea.

When it comes to far-flung western adventures that pull me off the beaten path, it takes a true winner to get my attention, and the latest addition to my list of all-time great western multi-day packs is Stone Glacier’s Sky 5,900 on an Xcurve Frame. What makes it great? For starters, the Xcurve frame is as comfortable as they come. I applaud the large, sweatproof lumbar support pad centered in the middle of the hip belt via Velcro attachment. The Powerlock Hip Belt’s padding conforms to the hips, and upper and lower hip-belt adjustments ensure a perfect around-the-waist hug. Another top-end feature of the frame’s belt is the Forward Assist Pull, which means no slip on the hip. The tighter you pull the belt, the tighter the lock on the webbing. This feature was much appreciated, especially by someone with a 31-inch waist hauling a load north of 80 pounds.

The shoulder straps on the Xcurve Frame deliver comfort in spades — wide, padded supports run parallel along each side of the spine, starting just above the waistline. The pads can be moved via Velcro attachments, and, of course, the part of the straps that come up and over the shoulders and down the chest is adjustable up/down via nylon straps. A center chest strap helps secure the pack by connecting the two shoulder straps.

I also tip my hat to the Xcurve’s meat-hauling ability. This pack was made to tote like a dream even when loaded down heavily. On a recent trip for bighorn sheep, I packed hide, horns, and meat. The integrated load shelf and multiple nylon-and-buckle straps sucked the load down tightly, kept the weight centered, and prevented side-to-side shift. The descent off the mountain was a gnarly one, and I put the frame’s comfort and ability to haul a load to the test. It passed with flying colors. The stays, which make up an “X” shape, are 4 Carbon Fiber and are bulletproof. The anatomically matched curvature of the frame fit my body perfectly and seemed to conform to each feature of my back. When you’re hauling a load, especially a load over distance, comfort is essential. The total weight of the frame, with a Medium belt, is precisely 3 pounds.

The Sky 5900 pack is a warrior. Ease of access is the big story with this pack. The front panel is fitted with a north/south heavy-duty YKK #10 zipper that provides immediate access to a large 22-inch front pocket. The pocket was spacious, and I found it ideal for my spotting scope and rain gear. The open side pockets with nylon belt adjustment are perfect for water bottles, tripods, and trekking poles. Rifle goers could also use them to slide their stock into. An oval-shaped zipper pattern and a drawstring closure on top of the pack provide instant access to the pack’s main compartment. In this location, I stored my sleeping bag, glassing pad, one-person tent, food, stove, and the list goes on.

I was also a fan of the Sky Lid, which proved ideal for sucking the horns down to the pack, but primarily, the spacious single-zippered pocket provided right-now access to snacks, knives, wipes, extra wind checker, and the like. This lid is an accessory item and will need to be purchased separately. While I choose to store my hydration bladder in the pack’s main compartment, the lid is also an excellent place for it. My only issue was a personal one: I was not too fond of the sound of sloshing water close to my ears.

The bag has a fighting weight of 2.7 pounds, and over two months of testing the bag, it proved to be German-tank tough. It attaches quickly and easily to the frame, and I love the pair of slots that slide easily over the top of the frame’s stays. The zippers never failed. They held up to inclement weather, and the combo of Cordura 500 and Xpac fabric promises years of worry-free use.

While the pack doesn’t have a designated bow pocket, the numerous buckle straps that run across the pack’s front for compression held my Hoyt with ease.

Stone Glacier doesn’t do anything halfway, and there are a few accessory items (side of the lid) you’ll want to add to your purchase. First is the Large Accessory Pocket. This 2.3-ounce pocket is spacious and attaches easily to the frame’s belt. It’s excellent for needed-right-now items. Another ad should be the Rain Cover. The cover stretches over the pack, rolls up to nothing, and stores in a small included dry bag.

This pack is one of the most efficient, comfortable, and durable packs I’ve ever used. It will be a mainstay in my pack line for years to come, and I can’t wait to log some more miles with it.