They don't currently though. I've never seen them with any Virginiana hybrids. They have a live oak cross, but it is a scrub live oak that never gets tree size, well, not shade tree size. I guess I have enough trees in the yard anyway.

There's a yellow red oak cultivar called 'Aurea' that is pretty yellow in spring (red oaks are yellow when they leaf out anyway). Otherwise the one seen here that really stands out is the 'Concordia' English oak, that stays quite yellow for a long time and is almost too much.

Dan, the name of the blue and valley oak hybrid is Quercus × jolonensis Sarg. (Q. douglasii × Q. lobata Nee). It is listed in that link you posted. My source for the Q.kelloggi x Q.lobata hybrid is here: http://www.laspilitas.com/groups/oaks/california_oak2.html and http://www.laspilitas.com/groups/oaks/california_oak4.html They even have a picture in the second link. http://www.laspilitas.com/images/grid24_24/4645/groups/oaks/pictures/kellogii_lobata2.jpg

I would also opt for something other than the oaks. If you are still going for a native tree I would choose the native hybrid Aesculus 'Homestead' or the Homestead Buckeye. It is resistant to the common leaf blight Ohio Buckeye has at the end of the year and is perfect for a prairie setting with outstanding orange fall color and a perfect rounded crown. Another great choice would be Aesculus 'Autumn Splendor' which is a University of Minnesota release that has red fall color. Both trees will mature in the 20' range and are resistant to the leaf blight that commonly disfigures other buckeyes and horse chestnuts. They will produce fruits so are not recommended right by a sidewalk. Other options would be the dwarf river birch Fox Valley or Little King, and you could also do Blackhaw Viburnum (Viburnum prunifolium). There is also a dwarf oak release from NDSU called Prairie Pioneer which is more of a single-stemmed, non-suckering dwarf oak. Only problem is that it is very hard to locate in commerce and I have never seen them available for sale. If you wanted to go with something non-native there are two newer Ussurian Pear varieties, Mountain Frost and Prairie Gem. Prairie Gem would give you a dwarf tree in your range. Overall I prefer the buckeye as it has that "native look" and you probably won't find them planted nearby.