Turgay Plateau
The land here is somewhat higher than the West Siberian Lowland, and--arguably--connects the Urals to the Kazakh Uplands(1) to its northeast.
Footnotes
(1) Kazakhskiy (or Kazachskij) Melkosopochnik (or Melkosopocnik, with a diacritical on the c) in transliterated Russian.