Sierra de la Demanda  Sierra de la Demanda is a mountain sub-range situated in the northern Iberian Peninsula. The Sierra de la Demanda area provides the habitat for "Lissotriton helveticus punctillatus" (Schmidtler 1970), a subspecies of the palmate newt. The Sierra de la Demanda is part of the western section of the larger Sistema Ibérico. The sub-range runs through the eastern province of Burgos and western La Rioja, bordering on the Meseta Central in Spain. The highest peaks of the range are usually covered in snow between October and May every year. Valdezcaray ski resort is located in the Sierra de la Demanda. The Picos de Urbión are located south of this range.