Hi! My husband's family are Van Kootens. HIs grandfather Reijer (Roy) was one of 17 who came from Apeldoorn, the Netherlands about 1910. I know there are still many Van Kootens in that area and in the Barneveld areas.
When we were in the Netherlands, we asked about the origin of the name and were told "Kooten" is the plural form of "cotes" such as pigeon cotes or dove cotes. Others have told us that Kooten is a town, but we have never been able to find it. I think the first explanation is more likely.
Valerie Terpstra Van Kooten