In the lower 10 miles (16 km) of its course, it has a very sinuous channel filled with sand and gravel bars, making the water shallow and navigation for small boats difficult.
The alluvium includes pebbles derived from bed fock, light micaceous sands, and in some places quicksands.
Preparations were being made in 1908 for working claims here on a more economical scale with water brought in a ditch from another tributary of Fox River, known as Blue Rock Creek.
[4] Along Fox River, about 10 miles (16 km) south of Council, there are several dikes of greenstone that under the microscope are found to be slightly altered diabase.
Some greenstone masses which appeared to be slightly altered tuffs were found in the divide between Fox and Solomon rivers.