Detect river when moving troops?

Is there any good indication to see when you are crossing rivers or is this only shown visually on the map itself?

Take London and Bedfort for example, is there a river in between those counties? There is on starting in the middle of Bedfort but it lies behind it's city. If there is no river then would there be a river between Northhampton and Bedfort? I cannot find a UI indication about this, that would be very handy.