As others have posted (http://denver.craigslist.org/fgs/ html -AND- http://www.bbb.org/denver/business-reviews/landscape-contractors/yankees-landscape-and-concrete-in-denver-co-90226453), this is a scam operation.
Lopez takes your deposit for most of the work & then disappears.
He has a criminal record of felonies. He also goes by several other aliases including "John Manzanares", "Jay", "Mia" and "Jake" (and probably others).
He was just arrested on Aug 27th for "Fugitive from Justice" (fleeing another state while that state has a warrant for his arrest), but he is on the loose again and once again scamming and stealing your money!
He uses the phone numbers:
Here's a link to all of the CL URLs he's conducting his scams under:
http://denver.craigslist.org/search/bbb?query=aaa+concrete
http://denver.craigslist.org/sks/ html
http://denver.craigslist.org/fgs/ html
http://denver.craigslist.org/sks/ html
His registered business name is "Yankee Concrete".
Picture of his face AND truck are attached. Temporary tag 202589N and it expires on 10/9