The Red Rock Line was a boundary separating the Sac and Fox Indian tribes from white settlers expanding westward. Its survey began on the red sandstone bluffs north of the Des Moines River in what is now known as Painted Rocks, and the line extended south to the Iowa/Missouri border and north to a point in Hardin County near Steamboat Rock. Created by the treaty known as The New Purchase of 1842, it allowed the United States government to purchase 12 million acres of central Iowa for $800,000. The treaty became effective on May 1, 1843, by which time the Indians had to depart the land east of the line. On October 1, 1845, the Sac and Fox departed the area west of the line, and settlers then staked their claims to the land. After a few years, several of the Indians returned to Iowa and purchased some of their former land near the town of Tama. Red Rock, the first town in Marion County, was founded by John D. Bedell, who established a trading post there and platted the town. Additional trading posts were built nearby, and the frontier town became an important river port with several sawmills and gristmills. It flourished until the railway was located several miles to the north and the nearby red sandstone quarry closed in the late 1890s. Located on the Des Moines River at the base of the bluff one-quarter mile south of Red Rock Cemetery, the town was flooded many times throughout its history, was considered as a site for Iowa's new capital until a flood cooled interest, and was permanently flooded in 1969 when Lake Red Rock was created. Red Rock Cemetery is all that remains of the once booming town. The Sac and Fox and later traders and others also used the nation's second largest Sycamore tree just south of Red Rock as a gathering place, and the trunk of the Treaty Sycamore can still be seen in the lake.