Alitalia has Casablanca, Morocco on sale in the $400s from cities across the USA including $462 round trip from Los Angeles and $477 San Francisco to Casablanca. These flights are searchable on Google Flights and available for direct booking on Alitalia US website. For some dates I checked there was no direct link from Google Flights to Alitalia fares and other dates showed a direct link. For dates with no direct link, I was able to find the low fares directly on Alitalia website.
There are limited departure dates from January to May 2017.
Alitalia Los Angeles LAX – Rome FCO – Casablanca, Morocco CMN – Rome FCO – LAX
Alitalia San Francisco SFO – New York JFK – Rome FCO – Casablanca, Morocco CMN – Rome FCO – JFK – SFO