The Algero-Moroccan frontier region which the French army conquered between 1881 and 1912 is a deprived, desolate land of crags and barren steppes, its aridness symbolized by the great funnels of dust which hot winds push aimlessly back and forth across the desert. The harsh environment of southeastern Morocco was still not so arid as to preclude human adaptation to it. Indeed, during the later nineteenth century, in the neighborhood of two hundred to two hundred and fifty thousand people inhabited the region, surviving, and in good years thriving, on the resources which the sparse rains made available. The Ziz, the Guir, and the Zousfana rivers, lying approximately parallel to each other, provide good reference points for a geographical overview of the region. By 1900 the Ait Izdig were on the way to complete sedentarization, although part of the tribe continued to live in tents and make short seasonal moves around the upper Guir and the Ziz valleys.