Being classified as a desert has to do with how dry the climate is not specifically the terrain. If a snake lives in a desert area doesn't mean they only live in the sand. Deserts still have plant life area. Kelowna BC is a desert type climate and they don't have any desert (sand) areas in the sense you are meaning. Bull snakes can live in your area and might even be seen in the sand but that doesn't mean that is where they would spend the most of their time. They would generally live more near a water source which would also be a generally area 'with more soil and plants then sand. Bull snakes are also very common it Alberta Canada. That's a forest area not sandy. Also if you took one from the wild there (which you wouldn't because its illegal there) you wouldn't grow grass in a tank for a substraight you would still use shavings, paper towels etc. Sand is actually more abrasive then people may think. If you have your bull on it all the time it would eventually dull out his colors a little from minor scratching. Not a big issue but still happens. Google "Bull snake care". It will give you pages with general information. Keep in mind though they aren't always a 100% accurate so you can also come back here to clarify stuff you might read as well. Or if you have other questions. Also I recommend a 4 foot tank at least. Some of the care sheets you might look up could say smaller then that because they aren't a big snake but they are active like already mentioned so a bigger tank is better.