Question
How much soil is a "yard"?
In a truck or trailer?
Dumped in a pile?

Answer
Doug,
   A cubic yard is 27 cubic feet, per cu.ft. soil weighs about 90 lb. for sand more for gravel(maybe 100+ for large rocky gravel), loam 75 lb. and clay about 65 lbs.  This makes a yard weigh about a ton.  A 6 ft long pickup bed could hold 1.25 yards level probably about the same if heaped up but slanting down.   So most pickup can't carry more than a ton comfortably.
Bryan