Table schema:
CREATE TABLE table_name_93 (structure_height_ VARCHAR, m VARCHAR, name VARCHAR, country VARCHAR, year VARCHAR, type VARCHAR)

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 table_name_93 WHERE year < 1968 AND type = "te" AND country = "united states" AND name = "fort peck dam"