U.P. TREE  IDENTIFICATION  KEY
from Michigan State University Extension

Picture Hint

  Short leaflet stems, under 1/8-inch.
                                        Bitternut or Black Ash

          or

  Longer leaflet stems, usually over 1/8-inch.
                                        Green or White Ash

You have selected a broad-leafed tree
with branched compound leaves,
with four or less pairs of leaflets,
and indistinct teeth or nearly smooth
leaf margins.