Indiana's ghost towns were not mining camps. Most were mill seats, river towns and farm hamlets that lost their reason to exist. In the southern hills, early towns grew up at falls and springs: Hindostan Falls, on the East Fork of the White River, had about 1,200 people by 1820 until an epidemic killed or drove off most of them. Wikipedia dates the outbreak to 1820 and the state's 1966 marker to 1828. Spring Mill's stone gristmill of 1817 stopped in 1892 or the late 1890s (the state's history of the village gives both), and the village fell into ruin. Prophetstown, the Shawnee-led town of 1808 on the Wabash, was burned by American troops in 1811. At Lick Creek in Orange County, free Black families farmed their own land from 1831 until the last of them sold out in 1902.
In the 20th century, public works emptied towns. Salamonie Lake covered Monument City in the 1960s, the Army Corps of Engineers bought out Elkinsville for Monroe Lake, and land condemnation for the Indiana Dunes National Lakeshore ended Tremont. On the Ohio River, the 1937 flood wrecked Leavenworth, and the town rebuilt on the bluff above.
Little stands at most sites. The state restored Spring Mill's village from the late 1920s, and Prophetstown State Park has a re-created village. Elsewhere expect cemeteries, foundations, square mill holes cut into riverside rock and historical markers.