Trying to identify mystery tree on UW campus

I love the fact that (at least parts of) the University of Waterloo campus has been planted with a variety of trees. There's one particular tree that I've been trying to identify. The bark of this tree has an odd gray mottled camouflage pattern to it and the seed pods formed in the fall are spherical bundles of small, long seeds with feathery wings. The pods fall apart into a mass of yellowy fluff when you grab it off the tree in the spring... which is what I did this year after passing the tree uneventfully for about four years on irregular walks through the campus.

See the map for it's location on campus.

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The tree sits on the outside of Ring Rd. near Federation Hall just across the road going to the student villages. Included are some pictures of the seeds next to a quarter (after the fuzz has been removed) and a portion of the squashed seed pod. I wish I had a photo of the leaves, but they were not out yet the last time I walked by.

Does anyone know the species of this tree?

Update: My sister-in-law figured it out. It's a sycamore tree. Photos of seeds and bark on the Early Forest website confirm it.