The Motlatse River ("Permanent River"), Blyde River (Afrikaans: Blyderivier "Glad River"), or Umdhlazi River is a river in the Mpumalanga and Limpopo provinces of South Africa. It has a northwards course in steep-sided valleys and ravines of the Mpumalanga Drakensberg, before it enters the lowveld region of the Limpopo province. It has its ultimate origins at around 2,000 m altitude in the conservation area, to the north of Long Tom Pass. It runs through the Blyde River Canyon.