The department is more or less rectangular, more than three times taller (north to south) than wide (east to west). There are four geophysical zones, three of which are parts of the Andes system: the Western(2) Range(3), the Royal(4) Range and the High Plain(5) between them. The Western Range is represented only in La Paz's southwest; it continues in Perú. Heights above 5,000 meters are reached at Mount(6) Serkhe. The Royal Range is even higher than Serkhe, topping 6,000 meters in several peaks, with Snowypeak(7) Illampu the highest. Between them the High Plain averages over 3,500 meters. It contains the southeast end of Lake Titicaca(8), which continues into Peru. South of there, a fan of rivers drains into the lake.
The non-Andean zone is tropical lowland forest, and is beyond the Royal Range in northern La Paz; it is part of the Amazon(9) Basin. The Beni River system dominates the east slopes of the Royal Range as well as northern La Paz. The northwest fringe of the department belongs to the Madre de Dios(10) River proper, the mother of the Beni, and is one of the two source streams of the Madeira(11).
The majority--perhaps 17 in 20--speak Aymara as their first language. About two in 20 speak Spanish as their birth tongue, but many others learn it. About one in 20 have Quechua as their mother language. Most people are Roman Catholic Christians who have reconciled pre-Christian life cycles and world views to the European church. A few practice exclusive non-Christian ways; they are, for example, attentive to spirits of mountains (achachilos or machulas(12)) and to other spirits connected with irrigation waters. These physiographic identities are conflated with object and ancestor assocations.
People probably arrived here more than 10,000 years ago, probably from the north. The Aymara are the oldest known local culture, having been around at least 3,500 years. The Spanish, and Christianity, arrived by violent conquest about 500 years ago. The Quechua arrived not long before that, with the expansion of the Inca Empire.
northwest, from the north
north and east, from the north
east, from the south, and south
southwest
west, from the south
west, from the center
(1) Translates from Spanish as 'Peace'.
(2) Occidental in Spanish.
(3) Cordillera in Spanish.
(4) Real in Spanish.
(5) Altiplano in Spanish.
(6) Cerro in Spanish.
(7) Nevado in Spanish.
(8) South America's second largest lake (assuming Maracaibo counts as a lake).
(9) South America's longest river; the world's second longest.
(10) Translates from Spanish as 'Mother of God'.
(11) South America's third or fourth longest river; a tributary of the Amazon.
(12) Also spelled mallkus.