The Bigleaf Maple has 8-14inch leaves. Because of it's cool habitat, the bark is often patchy with interesting lichens.
To sprout the seeds, place fresh seeds in a plastic bag filled with moist but not wet mix of 1/3 sand, 1/3 soil, 1/3 humus, and refrigerate for 3 months, and then plant the seeds in a deep container with soil mix kept moist.