The May 30 launch of an "Oregon Trail" expansion pack in the popular Facebook game Frontierville has caught notice of the company holding the copyright to the edutainment classic, and it has sued to put a stop to the plans of Frontierville maker Zynga.

The lawsuit, filed by The Learning Company in federal court in Massachusetts, alleges that Zynga cut a trailer for its "Oregon Trail" missions (above) that highlights similarities between them and the The Oregon Trail notably "setting up a wagon, provisioning, hunting, fording rivers, and helping others." For the record, the trailer refers not to dysentery but "the Rocky Mountain Scoots."

The Learning Company says that Zynga's "Oregon Trail" branding is "deliberate theft of the goodwill associated with the iconic The Oregon Trail Mark, which the company has spent millions of dollars promoting since 1971."

The suit also claims that The Learning Company approached Zynga with a proposal to make a Facebook version of the classic game. After those talks fell apart, The Learning Company went to another developer.

Oregon Trail Copyright Owners Sue Frontierville Maker

The Learning Company Suing Zynga Over Oregon Trail Trademark [Gamasutra]