Protected marmots... (the term "chuck" is a misnomer)
The hoary marmot, is a creature of extreme altitude, and not readily found anywhere we can drive to, in this state.
Large, grizzled, gray colored dudes, similar in size to a raccoon, and often fairly tame.
The Olympic marmot, the most rare of our protected marmots, is unique to western Washington, one of the few strongholds with a decent population is on Hurricaine Ridge, inside the Park, so even if they weren't protected specifically by species, they'd be off limits to hunting.
The (pallid) yellow bellied marmot is what we can hunt.
They range along the Colombia, Snake, and Yakima Rivers, from Central Oregon, up through Eastern Washington, and into South Central British Colombia.
I always see them on the rocks, along the freeway (I-90), from Sprague, to Airway Hts.
These ranges are now overlapped, by the northward expansion of the California spotted ground squirrel, which can be found as far north as the LT Murray Wildlife Area, between the Columbia and the Pacific Crest... with some excellent opportunities around the Yakima Rez and surrounding orchards, for both species.
A third digger, the pocket gopher, can be found all over eastern Washington, with a good chance for shooting, from southwest LT Murray, down through the Coweechi, and on down Hwy 97 all the way to Oregon.
Their tell tale throwing of dirt, belies their tiny size, allowing targeting over a large areas.
But because you are "ground blasting" them (as opposed to targeting their bodies), larger calibers with highly frangible bullets are more effective.
Chuck,
If "around the Tri-Cities" is your number one criteria, I would look up towards Dayton, through Pomeroy, and along the breaks at the west margins of The Palouse country.

LTL,
The marmots that are protected, have been for many years, it''s not a recent thing.
But their status might become more severe, including listing as endangered, due to recent epimemia, the encroachment of new species, habitat loss, etc.
Krusty
