What plant hardiness zone is Powder River

Powder River is located at Natrona County, Wyoming (WY), USA.

Plant hardiness zone (winter frost zone or gardening zone) for Powder River is 4b by the USDA scale.

Coldest zone's winter temperature is −25 … -20 °F.

Plants of 4b USDA hardiness zone suitable for outdoor gardening and growing in this winter frost zone 4b USDA.