I spent the morning looking up tree leaves and I finally narrowed the 2 maples in the back yard down to this - Acer Rubrum, shown in the picture above. My leaves look like the top two small leaves. According to the references I found (from Oregon State no less) my tree could also be some variation of this species. Apparantly there is a maple that is often a cross between the red maple and the silver maple (which I originally thought my trees were) which is called a Freeman maple. There are three kinds of Freeman Maples and my leaves also look like one of those: the Armstrong Maple, shown below.
The issue I have with my tenative identification is that my leaf is not as flat at the base where the stem attaches to the leaf as the first picture, and is very serrated on the edges.But hey, my leaves are turning red!!! So I am close.