Yup, that water came from a glacier - no question - what a blue!
Sure did! The main source of water for this lake is not in fact from the glaciers in the mountains as you would assume, it comes from a huge glacier covered by dirt that you can see part of beneath the large rockface, about 2/3 to the right of the photo. It extends for hundreds of feet to the right behind those trees through a valley. We actually took a hike around there, and the glacier is covered in dirt the whole way around, though little patches of dark blue can be seen in a few spots
You can actually JUST make out a white spot at the back right of the lake, which is a series of small waterfalls coming from the glacier's melt.