What is this tree?
The tree in your picture looks to be a Norway maple, Acer platanoides, not a sugar maple, Acer saccharum. A good characteristic for Norway maple identification is the milky sap that is exuded from the petiole (leaf stem) when it is broken. Sugar maples have clear, watery sap.
Here is a good resource for more information on sugar and Norway maples. Oregon State University Landscape Plants
At this site, if you scroll down below the Acer sacchrum you will see a comparison between the two maples.