Distribution Comments:
Portneuf Chert is associated with the Portneuf Limestone Formation of the Thaynes Group of southeastern Idaho. Primarily occurs as nodules and seams at the head of the Portneuf River, Idaho. Most abundant chert occurs in the northwestern section of the formation at Fort hall about 60 miles northwest of Red Mountain.
Portneuf Chert is associated with the Portneuf Limestone Formation of the Thaynes Group of southeastern Idaho. Primarily occurs as nodules and seams at the head of the Portneuf River, Idaho. Most abundant chert occurs in the northwestern section of the formation at Fort hall about 60 miles northwest of Red Mountain.
