This study is an effort to document the genetic variation and genetic parameters of juvenile characters in the eastern cottonwood (Populus deltoides Bartr.) population of the southern Great Plains, and to preserve eastern cottonwood germplasm of this region for future genetics and breeding research. Funds for this work were made available in part by a grant from the United States Forest Service, Southern Forest Experiment Station and in part by McintireStennis, Oklahoma Agricultural Experiment Station.