Lumber Species in Phoenix

I have to evaluate adding equipment to an existing wood framed floor in Phoenix.  It is 2x12’s at 16” o.c.  I assume the typical lumber in Phoenix is Doug Fir.  Is that correct?  If so, is north or south?  What is the typical grade number of 2x12’s bought off the shelf at Home Depot?

 

Thanks.

 

 

Rich