Buchanan Creek is a left tributary of the Nodaway River and joins it 2.2 miles after its source at the confluence of the East Nodaway and West Nodaway rivers. It is the first named tributary of the Nodaway River proper and the only such one in Iowa. A small portion of its watershed stretches south in Missouri.
Course
Buchanan Creek sources just south of New Market near Iowa 2 and travels southerly along the Page-Taylor county boundary for about 4 miles. It then turns into Page County and travels southwesterly for 5 miles, passingRoss Park to the north. Lastly, it turns west and continues for about 2 miles before its confluence with the Nodaway River almost 2 miles north of Braddyville.