loganfoxtrot's Identifications

This is an example of the many trees in my yard that I came across my clear cutting a small section. With my knowledge, I would identity this as some type of maple tree. There were probably between 50 and 75 individual trees. Some were just starting as shoots (less than one foot tall) and some were upwards of 15 feet tall. The thickest tree was probably a maximum of 2 to 2.5 inches thick (diameter). These trees were growing in a 15 by 40 foot area, in the presence of these large pine trees (each about 60 feet tall). The leaves on these trees have a shiny red finish. I am curious if someone could confirm or deny my identification and tell me what type of tree this is.