A two story high maple tree has simple leaves with three uneven lobes is located in south side of Mount Pleasant Park in Vancouver one week ago.
and, +1. Also although Michael doesn't like to admit it the accepted name is Acer tartaricum ssp ginnala (ducks and runs for cover).
Accepted by some, but not by others ;-) The case for lumping them is pretty poor - they're easily distinguished, and separated by something like 3-4,000 km range gap. It's about the same as trying to argue for e.g. Acer campestre subsp. miyabei.