The Tar Seeps of McKittrick, California. Part II. Product of the Tar Seeps of McKittrick

In the belt of oil fields on the southwestern border of the Great Valley of California occur tar seeps which in times past have trapped creatures in somewhat the same way that the tar pools mired animals in the famous Rancho La Brea deposits of the Los Angeles basin. As in the instance of the latter well-known locality the seeps a long the margin of the San Joaquin Plain have preserved their organic record from the Ice Age.