The habitat has long been modified by farming, ranching and logging and is now threatened by construction of hydroelectric and irrigation dams.

[3] The Marañón River rises on the Nevado de Yapura glacier, and runs northwest through northern Peru between the western and eastern cordilleras of the Andes.

[4] The ecoregion's most southern part is in the Tayabamba District to the west of the Rio Abiseo National Park.

[8] The ecoregion holds seasonally dry tropical deciduous forest and arid or riparian scrub.

[9] Characteristic species include Acacia macracantha, Athyana weinntanniifolia, Ceiba insignis, Cordia iguaguana, Cyathostegia mathewsii, Eriotheca discolor, Eriotheca peruviana, Geoffroea spinosa, Hura crepitans, Krameria lappacea, Llagunoa nitida, Parkinsonia praecox, Praecereus euchlorus and Rauhocereus riosaniensis.

[2] Endangered birds include the yellow-bellied seedeater (Sporophila nigricollis) and Marañón spinetail (Synallaxis maranonica).

[2] Plans to build a series of 20 hydroelectric and/or irrigation dams on the Marañón River were announced by President Alan García in April 2011.

18 of the dams would be in environmentally sensitive areas, include the dry forests, and would displace indigenous people and other farmers and fishermen along the river.