Related by context. Frequent words. (Click for all words.) 60 cliff dwellings 59 Hohokam 59 Chaco Canyon 57 petroglyph 56 Petroglyphs 56 adobes 56 archeological 55 archaeological 55 archeological sites 55 Anasazi 54 archaeological sites 54 Inca Empire 53 steep ravines 53 petroglyphs 53 Cagsawa 53 earthen mounds 52 cypress swamp 52 midden 52 Chihuahuan Desert 52 Excavated 52 pre Incan 52 presidio 51 Canyon de Chelly 51 prehistoric 51 limestone cave 51 lava tubes 51 arroyos 51 Hatra 51 Harappa 50 limestone caves 50 Sierra Madre Mountains 50 coquina 50 wildlife corridors 50 ancient Mesopotamia 50 Superstition Mountains 50 erosional 50 archaeologically 50 Meteor Crater 50 ancient 50 archaeological ruins 50 archaeological finds 50 Encroachments 50 sandstone cliffs 50 middens 50 Huachuca Mountains 50 Sassanid 49 mesa 49 adobe brick 49 ranchos 49 Cerro Rico 49 Omo River 49 Achaemenid era 49 rock outcrops 49 archaeological artifacts 49 escarpments 49 sparsely inhabited 49 buttes 49 Kartchner Caverns 49 riparian vegetation 49 ancient civilization 49 Olmecs 49 burial mounds 49 Judean Desert 49 desert scrub 49 archeological digs 49 Sierra Madre mountains 48 Caral 48 de Anza 48 Lassen Peak 48 prehistory 48 coastal dune 48 oak savanna 48 Agua Fria River 48 Palenque 48 palisade 48 excavated 48 Amazonian rainforest 48 stelae 48 moonscapes 48 landform 48 riparian zones 48 dry riverbeds 48 Las Chepas 48 karst 48 fertile plains 48 El Mirador 48 olive orchards 48 Fertile Crescent 48 Archeological 47 Durrington Walls 47 Ottoman rulers 47 Painted Desert 47 Hittites 47 Sonoran desert 47 Inca empire 47 diggings 47 ancient tombs 47 Miwok 47 temperate rainforest 47 Tenochtitlan 47 streambanks