Both the North Wyaconda River and South Wyaconda River begin in Davis County, Iowa, just south of Bloomfield (Figure Lo01). They flow in a southeasterly direction for approximately 45 miles before they join, forming the Wyaconda River. The river continues to flow in the same direction for 47 miles, where it enters the Mississippi River north of La Grange, Missouri at river mile 337. Seventy-three percent of the watershed is within Missouri, which drains portions of Clark, Lewis, and Scotland counties. The basin is only 5 to 8 miles wide along its 70 mile length. Major tributaries (3rd order or larger) to the Wyaconda River include the Little Wyaconda, Sugar Creek, Ramsey Branch, Little Sugar Creek, Crooked Creek, Hickory Creek, Derrahs Branch, and one unnamed tributary. Major tributaries to the North Wyaconda River include Billups Branch and three unnamed tributaries. The South Wyaconda River has three major tributaries including Allen Creek and two unnamed tributaries.
The basin drains 458 square miles (293,120 acres), of which 336 square miles (215,040 acres) lie within Missouri. Both the North Wyaconda River and South Wyaconda River drain approximately 80 square miles each, composing 38% of the basin in total. The Wyaconda River is the only fifth order stream within the basin.
Streams were identified on USGS 7.5-minute topographic maps and ordered according to Strahler (1957). There are 18 third-order and larger streams within the basin (Table Lo01). The Wyaconda River is the largest (fifth-order) and longest (47 miles) stream within the basin. The North, South, Little Wyaconda and Sugar Creek are the only fourth-order streams within the basin. All remaining streams are third-order or smaller.