Heavy-bodied yellowish-brown marmot of rocky areas of western North America(noun)
WordNet. Princeton University. 2010.
Use "rockchuck" in a sentence
"(Also called a "rockchuck", if it happens to be found on a rock, like this one.)"
"The rockchuck, or yellow-bellied marmot, found from California, Texas, and New Mexico to British Columbia and southwestern Alberta, is another close woodchuck relative."
"We stopped once to watch a big fat rockchuck grubbing around a bunch of wineberry bushes."