Table: largest_dams
Columns: name
country
year
structure_height_m
structure_volume_10_6_m_3
reservoir_volume_10_9_m_3
type

Question: What is the height of the fort peck dam which was built before 1968, is located in the united states and has a dam type of TE ?
SQL: SELECT "structure_height_m" FROM largest_dams WHERE "year" < 1968 AND "type" = 'te' AND "country" = 'united states' AND "name" = 'fort peck dam'