Early Pioneers began to arrive to the area in 1843. The first settlement was on the LaCreole Creek. James O'Neil had come to Oregon as a member of the Nethaniel J. Wythe party. He built the first gristmill, where O'Neil's Creek flowed into LaCreole Creek. In 1844 families began to arrive by wagon train to settle along the LaCreole Creek near the mill. O'Neil also offered a general store and lodging for visiters who came for flour and other supplies as well as miners making their way to the California Gold Rush. In 1849 a flood destroyed the gristmill and James O'Neil sold out to James W. Nesmith and Henry Owen. The gristmill was rebuilt and named Nesmith's Mill. It was later sold to Reuben P. Boise, who had the adjoining donation land claim. The area was renamed Ellen's Dale after his wife. Later becoming Ellendale and hosted the first official post office in Polk County, opening on January 8, 1850.