A trench 1 mile long is to be excavated to an average depth of 8`. The trench base is 4`. Vertical sides are 5`. The top 3` of the trench are sloped at 1:1. What is the total amount of cubic yards excavated from the trench?

A trench 1 mile long is to be excavated to an average depth of 8`. The trench base is 4`. Vertical sides are 5`. The top 3` of the trench are sloped at 1:1. What is the total amount of cubic yards excavated from the trench?