801 Grand, also known as the "Principal Building", is a skyscraper in Des Moines, Iowa, United States. It is named after its street address, being located along Grand Avenue in the downtown area of the city between 8th and 9th streets (with High Street the northern border). Completed in 1991 and standing at 630 feet (190 m), it is currently the tallest building in the state of Iowa. It is the tallest building from Chicago to Omaha and from Minneapolis to Tulsa. The roof is made out of copper sheeting that was designed to form a green coating of verdigris over time, much like the Statue of Liberty. However, unlike New York City, the air salt content in Des Moines was so low that the desired oxidation process failed. The result was the copper turned a dark brown.