West East 14000 Sangre de Cristo Mountains 13000 13000 12000 12000 11000 11000 10000 10000 SAN LUIS VALLEY 9000 Elevation (Feet, mean sea level) 14000 8000 Qa Tfg Tc 9000 Tlp 7000 8000 Qa 7000 Tsf 6000 6000 Tv 5,000 Tsf Tc Tv p–C pre-Tv 4000 5,000 4000 3000 3000 Monte Vista Graben 2000 Tv Baca Graben 1000 2000 1000 Tv 0 0 -1000 Alamosa Horst pre-Tv p–C -1000 p–C -2000 -2000 -3000 -3000 p–C -4000 0 2 -4000 4 Mi -5000 -5000 EXPLANATION Qa Alamosa Formation Tsf/Tlp Santa Fe–Los Pinos Formations Tfg Fish Canyon–Carpenter Ridge Tuffs Tc Conejos Formation Tv Vallejo Formation pre-Tv Pre-Vallejo; Blanco Basin Formation p–C Precambrian crystalline rock Formation contact, dashed where approximately located Fault, approximately located; arrow indicates relative movement