Like most budding shooters, varminteering, for me, once involved rimfire bullets directed at targets of opportunity. In the eastern New Mexico of my youth that meant rock squirrels, 13-lined ground squirrels and especially pasture-wrecking black-tailed prairie dogs and grass-gobbling black-tailed jackrabbits. With time these ventures came to involve centerfire rifles and precision handloaded ammunition. It was my way of becoming a rifleman and the excuse I was looking for to burn hundreds of rounds monthly during breaks from my formal education. The varmints wantonly mowed down during those early years eventually made deer and elk seem like child’s play, convincing me that bows and arrows would dominate my big-game hunting future.  

But the desire to turn small varmints into red mist never waned. If anything, the passion festered into obsession, until eventually only rifles spitting highly-frangible bullets into sub-¼-inch groups remained interesting in any meaningful way. Spring and summer calendars were marked against ambitious varmint-shooting forays to regions promising greater densities of uneducated ground squirrels or prairie dogs (P-dogs), places where barrels were burned out and long-range mettle tested — all shared with my gun-loony father, who would rather shoot burrowing rodents than all the fancy big game in North America. From my perspective, ground squirrel or prairie dog colonies were just as exciting as mountain mulies or bugling elk. 

Then I discovered rockchucks, more properly known as yellow-bellied marmots. Here I discovered my new varmint-shooting passion. It is difficult to put a finger on why, as they seldom provide the sheer shooting volume of a pasture or clear-cut overrun with Belding’s or Richardson’s or Columbia ground squirrels, or remote Wyoming or Montana prairie dog towns. Rockchucks certainly aren’t as outwardly challenging — not in the way of a tiny ground squirrel measured in ounces or distant prairie dogs shot across wind-swept plains. I mean, a good day of rockchuck shooting might include dozens instead of hundreds of targets engaged. And the average rockchuck weighs 5 to 10 pounds, making for a pretty fat target compared to garden-variety small-varmint fodder. The obvious question is why?

Pressured for a quick answer, I’ll immediately say the country appeals to me mightily — desolate expanses of southeastern Idaho foothill canyon country, or Colorado or Montana alpine splendor. Rockchucks undoubtedly inhabit prettier terrain than the average desert or clear-cut ground squirrel or monotonous P-dog short-grass prairie. But that’s not really the truth. 

Rockchucks offer the ultimate long-range challenge, because the best shooting perspectives are generally gained across wind-swept canyons, which means ranges automatically stretch to extremes. Those extreme ranges make you appreciate the rockchuck’s chubby physique, as canyon-land/mountain habitats are cursed by wind-drift treacheries. So that is really it. The more time you spend shooting small varmints, and the more serious you become about it, the more challenge you’ll eventually crave. 

With rockchucks, shots are seldom lacking challenge, and targets are harder won. Not that rockchucks are less numerous, it’s just that they are more difficult to discover while scouring cluttered rock piles and broken cliffs for potential targets. A sunning rockchuck blends with their rocky environment as convincingly as a kudzu-dwelling chameleon. It becomes as much a hunt as a shoot, with top-quality optics as important as a straight-shooting rifle. The shooting is a bonus, but also seldom lacking drama.

A Western Affair

The common moniker hints at habitats preferred by rockchuck; rocky areas and talus slopes found in mountainous or foothill regions of the West. There are several marmot species, but only yellow-bellied and hoary marmots concern varmint shooters. The yellow-bellied is most widely available, spread from southern British Columbia and southwestern Alberta south through eastern California west to Montana, Colorado and into northern New Mexico. They’re generally found at elevations from 6,500 to 11,000 feet above sea level. The hoary marmot is found in identical habitats, but limited to far-northern Washington and Idaho and western Montana, extending north into Canada and eastern Alaska.  

Besides established range, yellow-bellied marmots are distinguished by yellowish-brown bodies and yellowish bellies, typically sporting whitish spots between the eyes and brushy tails. They stand 18½ to 28 inches and weigh 5 to 10 pounds. The larger hoary marmot, or “whistler,” is silver-grey with brownish rump and white-hued belly, standing 17¾ to 32 inches tall and weighing 8 to 20 pounds. Its habits closely mirror those of the yellow-bellied. You’ll know you’re in rockchuck country when you began discovering 8- to 9-inch burrows with fans of packed earth spilling from rocky shelter and a prominence of moose-like droppings. Both are regularly located through whistling calls. Rockchucks, like black bears, hibernate through winter months (October/ November through February/March, depending on elevation and predominating weather), proving most active through spring and early-summer, appearing more sporadically through summer on overcast days or cooler hours.  

Colorado’s Rocky Mountains, particularly the West Slope, was rockchuck nirvana once upon a time, but the transformation from a red to deep-blue state following invasions from the People’s Republic of California initiated limited season dates (August 10 to October 15; license/permits $56 annual or $11 daily non-resident, plus $10 habitat stamp). Friends do quite well in central Montana, and Utah and Nevada high country must relinquish rockchuck shooting, but my preference is southern Idaho ($97.75 annual, $35 3-day non-resident license), including no seasons or limits, abundant rockchucks on endless acres of public lands, and at much lower —and more accessible — foothill elevations.

Chuck Gear

It is true scads of rockchucks are bagged each season with rimfire rifles — mostly by hunters stalking stealthily through rocky habitats and placing shots just so — but for my tastes the long-range angle is what makes rockchucks so fascinating. The general approach is to gain a vantage while glassing across canyons into opposing rimrock or investigating substantial, if sometimes scattered, outcrops. On certain BLM lands we conduct reconnaissance from inside 4WD vehicles, stopping to pore over likely rock formations with quality glass, as often parking to take short hikes into hidden canyon heads or to gain a closer look at promising geology. On public lands closer to major population centers (say, Boise) a willingness to hike gets you into more profitable shooting by distancing yourself from roads that are shot over more frequently. 

On private ground we’re often able to pull right up to field edges overlooking rimrock or ranch dump sites harboring healthy ‘chuck colonies. Depending on circumstance, namely how far you must venture from your vehicle, shooting is conducted atop portable benches and rifle cradles — my setup is a Big Game Treestand’s Swivel Action Shooting Bench and MTM Case-Gard’s K-Zone rest — or folding bipods like the original Harris or newer TRUGLO models. When shooting off bipods a standard-issue backpacker’s sleeping pad takes the edge off sharp rock while lying prone.

I’ve happily shot rockchucks with standard .223 Remington rifles (including ARs), my .204 Ruger and .22-250 Remington chambered in a tack-driving customized ’98 Mauser with heavy custom barrel. They all work well — until evil high-desert/mountain winds begin to stir. Turreted scopes (more in a moment) make elevation a no-brainer (granted you’ve built solid ballistics charts), and makes wind somewhat manageable (again, carefully assembled charts help).

But the problem is when shooting across sudden canyon cuts or wide expanses of prairie to reach distant rock outcrops, wind velocity is seldom consistent between shooter and target. Put another way, dialing out 12-plus inches of wind drift is entirely possible with quality turreted optics, but winds that vary by as little as 2 to 3 mph substantially widen margins for error. Few sub-.243/6mm-caliber bullets include decent ballistic coefficients (BC). When distances stretch beyond 300 yards, and wind stirs to velocities exceeding 5 to 7 mph, BCs of at least .450 cut that margin of error by half. 

Quick examples: a .22-250 pushing a 50-grain polymer-tipped bullet (BC .242) to 3,800 fps, subjected to a 7 mph crosswind, drifts 12.1 inches at 400 yards and 20.3 at 500. Conversely, a 6mm Remington launching a 95-grain polymer-tipped match pill (BC .500) to 3,200 fps, and subjected to the same conditions/ranges, drifts only 4.9 and 7.9 inches, respectively. With a rockchuck chest measuring, say, 7-9 inches across, implications are obvious. BC can also be boosted by shooting heavy-for-caliber bullets in standard .224-caliber cartridges — granted your rifle includes sufficient twist rate — faster 1:9 to 1:7 (standard in most ARs) verses common 1:12 to 1:10 (standard in most bolt guns). For example, a .224 50-grain (BC .242) opposed to a 75-grain (BC .435, and 1:8 twist recommended). Understand this has little to do with bullet weight, but aerodynamics as it relates to retained velocity and flight time. All bullets, regardless of weight, are subjected to the same degree of wind push, so the less time spent in flight, the less time wind has to influence its path. Regarding actual wind velocities; experience is the best teacher, but a quality aerometer (like those from Caldwell or Kestrel) help flatten learning curves, and provide solid starting points.  

You can shoot any cartridge you wish, of course, but I prefer to not be brutalized during high-volume varmint shooting. The popular 6mms are ideal, offering BCs well above the long-range maxim in weights from 95 to 108 grains, while producing wholly manageable recoil. My father’s 10-plus-pound Ruger Precision chassis rifle in highly-efficient 6mm Creedmoor (a rifle that assembles ½-inch groups at 200 yards with tailored handloads) is a perfect example. Its 1:7.7-barrel twist handles any 6mm bullet available. I shoot a 6mm Remington with custom Wilson, 1:9-twist barrel, which assembles sub-¼-inch groups with bullets up to 107 grains (1:8 twist typically recommended). There are also no flies on the venerable .243 Winchester.      

As hinted, when shooting long-range rockchucks I consider quality turreted, 30mm scopes mandatory. I also lean toward higher magnification for all things varmint related. Turrets allow applying knowledge instead of guesstimates, and allow precise corrections after a marked miss. When it comes to scope power, I always say you can’t hit what you can’t see. Favorites include Trijicon’s AccuPoint 5-20x50mm, Vortex’s Viper PST 6-24X50mm, Bushnell Elite 6500 4.5-30x50mm and Vortex’s Golden Eagle 15-60x52mm.

I can’t imagine abandoning ground squirrels or prairie dogs, as they provide more fun than a basket of frogs. But today it’s rockchucks that fill my off-season dreams and big plans for the coming season. To my mind they represent the “big game” of the varmint world, and everything that lured me into the varmint-shooting game all those years ago — pure sport, tinged with challenge, and yes, some of the most gorgeous habitats the sport has to offer.