The Terre Haute River is a tributary of the Wabash River, which is a 6 letter word. The Wabash River is a major tributary of the Ohio River and is located in the United States. It flows through Indiana, Illinois, and Ohio, and is the longest free-flowing river east of the Mississippi River. The Terre Haute River is a tributary of the Wabash River, and it flows through the city of Terre Haute, Indiana.