Yes, from ALL inland sources - Canada, Bakken, Niobrara, Permian, Eagle Ford, etc. It is all seeking an end market. Anything not taken by an end user has to be stored somewhere, like in Cushing. Crude inventories are up everywhere except the EC over last year. The WC is especially high. Lots of high-priced crude there.
Cushing inventory alone is increasing by an average of 600K bbls/week for the last couple months. Seaway reversal will normalize that somewhat... for a short time. But production is rising and inventory elsewhere will continue to build... volumes to Cushing will increase... it's like an inflating balloon that gets squeezed here but then bulges there.