The source of the River Hull and its mouth are particularly interesting points and seeing as they are loosely to do with geology I will deal with them here.
The photo above shows a wooded bank with dense undergrowth immediately north of the churchyard at Kirkburn (I was stood at the perimeter fence to take the photo), a village on the Yorkshire Wolds two miles south-west of Driffield. In the lower centre of the photo a trickle of water is just visible – this is the source of the River Hull, or at least the source of one of its headwater streams. The source is a spring in the hillside, this showing the height of the water table in the porous chalk bedrock. Even within the village of Kirkburn the trickle becomes a small stream over which the main Bridlington to Market Weighton road passes, the stream is called Eastburn Beck which is fed by small local tributaries before becoming the River Hull south and east of Driffield. Alongside Eastburn Beck are two deserted village sites, Eastburn Village (historic) and Sunderlandwick Village.
South-east of Driffield the upper River Hull follows a tightly meandering course alongside which was dug the Driffield Canal. This section of the upper River is still clear water and with the water having flown-out from the chalk bedrock provides ideal conditions for trout. In the 18th century the area became a place of resort for fly fishing, a popular ‘sport’ of the gentry. For those who travelled from far away hotel accommodation was built in Driffield. There is surviving evidence of modern trout farms alongside the River and drawing water from the River. Whether these are still functioning, or not, I am not sure.
Driffield Canal was built off Frodingham Beck (not the upper River Hull, Frodingham Beck being a major tributary of the River Hull, their confluence is just south-west of North Frodingham village.