Those trees are not endangered, so you can climb them more easily than you climb whitebarks -- with heavy spurs that strap to your boots and go up your calves like a brace, with another strap below the knee. You set your spurs into the tree's bark, toss your flip rope around the tree trunk and secure both ends of it to your harness, and move upward, flipping the rope up with you, spurring and climbing. If your spurs slip, the flip rope will catch on something and keep you from hitting the ground, but it's more than a safety device, it's the way you climb, putting your weight onto your harness and leaning back so you can stab your spurs deep into the bark. Scary at first, but the motion feels natural. When you reach a live limb, you grab it, unclip your flip rope, flip it above the limb and clip back in. You are truly safe then, though it takes a while to convince your mind of that.

Once you spur-and-flip-rope your way up to the top of a ponderosa, you set your mainline -- the rope you will use for your descent -- and start sliding down it, harvesting cones and dropping them into the pig. You can use your hands to twist the cones off the tree or use an extendable pole pruner to clip off the cones, which allows you to reach farther to work the tree from a more stable stance without moving around on your rope so much. The farther you extend the pole pruner, though, the faster you exhaust your wrists, forearms and elbows by holding it up and pulling the cord that operates the little cutting jaws at the end. The pole pruner is efficient until it gets clogged with sap. It's also the tool most likely to cause tendonitis in your elbows, while preventing the tendonitis in your wrists that you would get from twisting off cones by hand.

With the radical decline in whitebark forests, though, the harvesting of their cones is done more delicately, making it more interesting, and a bit more dangerous.

No forester in his or her right mind would permit a climber to stomp steel spurs into the last of the planet's whitebarks. You have to tackle the whitebarks in boots or shoes that won't hurt the tree. You can still use your flip rope for safety if you get spooked or exhausted, and let it dangle along behind you if you feel at ease. The one absolute is that there can be no loops, because anything that can snag, will snag, and it will snag at the worst possible time -- Murphy's law rules the heights of rock and ice and tree alike. As you climb, you jerk the pig through the branches, and drag your mainline -- sometimes a special arborists' rope that handles very nicely, or if you're a jackleg part-timer like myself, a sap-blackened old rock-climbing rope, clipped to a steel ring on your harness, right below your belly button, at your center of gravity.

When you get to the top of the tree, you secure yourself to the trunk or to a group of branches, using your flip rope. Then you unclip your mainline from your harness (shuddering, because if you drop it, you lose your finest ally, your partner in all that is safe and good), so you can pass it around a part of the trunk that is at least four inches in diameter, and tie the free end back to your harness, using a bowline or figure-eight knot that has about five feet of tail. Then you wrap that tail three or four times around the part of the mainline that is hanging down to the ground (you hope), making the high-friction, slide-able arborists' knot. You are now "tied in," and if you use your right hand to slide the friction knot down the mainline, you can control your descent, bracing your legs against the trunk or branches, leaning way back into the harness, removing the cones and placing them one by one into the pig instead of dropping them to the dirty forest floor, where they might be spoiled by fungus or other contaminants.

But before you start your working descent, there is usually one more adrenaline-pumping job: Crown cones that must be picked, way up there where the tree trunk is much too slender to support your weight. You must strip the required number of feet of slack through the arborists' knot, make sure that slack is not in your way, and climb up into that treetop. If you fall, if the top breaks out -- and they do -- you will go for a terrifying ride until your mainline catches you. Taking the crown cones is like leading a rock climb, and sometimes, at the end of exhausting days, or in the rain, or on bleary hungover mornings, you have to do it even when everything in your body is screaming, begging you to stay safely on your flip rope, safely tied in, with no slack in the system, no slack anywhere, please Lord.

And for whitebarks, in addition to no spurs, you can't use the cutting jaws of your pole pruner,  because they also might damage the tree or transmit fungus or disease. You can only use the pruner as a hook, to pull distant branches toward you to get the cones, an all-day pulling exercise that no rowing machine or wrist-curl bar in any gym can quite prepare you for.

When the pig is full of whitebark pinecones, you lower it so your partner can empty it and bag the cones in burlap, labeled with a meticulously filled-out tag, identifying species, date, place and the number of the tree or area. Then you tote bushel bags to the drop-off point and everything is loaded into a truck for transport to a big walk-in cone cooler at the nearest Forest Service work center.

The pigs are abysmally heavy and awkward when full, and the several-times-a-day lowering of a heavy pig, using a branch as a belay point, burns the kind of calories that can't really be replaced during the climbing season, no matter how much Nutella or cream cheese you slather onto your Fig Newtons, or how many Milky Ways you gobble down.