Rochers-de-Naye (near Montreux, Switzerland) is a nice place to see some Marmots up close in a nice surrounding.
The Marmot’s Paradise at Rochers-de-Naye is a steep, one hour train ride from Montreux. They have marmots from all over the world in large, open cages. Some of them are quite timid, others less so… Not quite the same as seeing these animals in the wild, of course, but you’re unlikely to get that close in the wild. Plus, they have Marmot souvenirs :-)
Walking back down to Montreux turned out to be a bit steep and sometimes slippery (thanks to the last patches of melting snow), but if you survive, the great views on the way down more than compensate for that.