What is the distance between St. Louis to Seattle?

2,140 miles taking this route:

1. Take I-70 WEST (towards Kansas CITY), from St. Louis, to I-29 NORTH to ST. JOSEPH, via I-435 NORTH to bypass KANSAS CITY (EXIT 8B off I-70 to get onto I-435 NORTH).
2. Take I-29 NORTH to I-90 WEST to RAPID CITY at EXIT 84B, near Sioux Falls, South Dakota.
3. Take I-90 WEST to Seattle.