I called the number. A message on their end said it was Elkhurst Communications, located in Willows, Ca. A search of their website reveals that "Elkhurst Communications is a data collection company that gathers information from surveys." They have an opt-out option for both email and phone numbers.
The BBB gives them two stars. The company is HQed in Mo.
http://elkhurstcomm.com/
http://www.bbb.org/denver/business-reviews/ma ... le-co-90141691/