Page Introduction 9 Historical 10 Classification 14 Villages 16 Rectangular ruins of the pure type 16 Surouaro 16 Goodman Point Ruin 17 Johnson Ruin 18 Bug Mesa Ruin 19 Mitchell Spring Ruin 19 Mud Spring (Burkhardt) Ruin 20 Ruin with semicircular core 22 Wolley Ranch Ruin 22 Blanchard Ruin 23 Ruins at Aztec Spring 23 Great open-air ruins south and southwest of Dove Creek post office 28 Squaw Point Ruin 28 Acmen Ruin 29 Oak Spring House 29 Ruin in Ruin Canyon 30 Cannonball Ruin 30 Circular ruins with peripheral compartments 31 Wood Canyon Ruins 32 Butte Ruin 32 Emerson Ruin 33 Escalante Ruin 36 Cliff-dwellings 37 Cliff-dwellings in Sand Canyon 38 Double cliff-house 38 Scaffold in Sand Canyon 38 Unit type houses in caves 39 Cliff-houses in Lost Canyon 40 Great houses and towers 40 Masonry 40 Structure of towers 42 Hovenweep district 44 Ruin Canyon 44 Square Tower Canyon 45 Classification of ruins in Square Tower Canyon 46 Hovenweep House (Ruin 1) 46 Hovenweep Castle 47 Western section of Hovenweep Castle 47 Eastern section of Hovenweep Castle 48 Ruin 3 48 Ruin 4 49