This little guy is a yellow-bellied marmot. They’re ubiquitous in tundras and talus fields such as this one near Morraine Lake in Jasper National Park. Most of these guys we met on the trail in the Sierras are used to hikers and would eye your backpacks with hunger in their eyes.
This particular guy wasn’t that interested in us though. He/she was more interested in chasing another marmot away and scurried away a second after this picture was taken.