A canal running along the Tsimiyank Reservoir from the city of Krasnoarmeysk on this river connects it to the southwesterly Don.
Medieval tombstones are the only surviving writing of this geographical feature's namesake dialect of the Bulgarian language. The podtzol soil around this river is notoriously poor, and it sections are marked by confluences with the Oka and Kama after it starts in the (*) Valdai Hills. A canal running along the Tsimiyank Reservoir from the city of Krasnoarmeysk on this river connects it to the southwesterly Don. A namesake city on this river was formerly known as Stalingrad. For 10 points, name this Russian river, the longest in Europe.
Medieval tombstones are the only surviving writing of this geographical feature's namesake dialect of the Bulgarian language.
the {Volga} River