The latest fall colors report from the Iowa Department of Natural Resources indicates it is peak viewing season in south central Iowa. Maple trees are showing bright colors. Hickory trees are turning yellow/brown, while Sumac and dogwood trees are bright red to deep purples. Walnut, cottonwood and silver maple trees are yellow and losing their leaves. Oak trees remain green, but will turn color soon. The peak season for viewing fall colors in South Central Iowa began Monday and goes through Friday.