The Collaborative International Dictionary of English v.0.48:

Laramie group \Lar"a*mie group`\n. (Geol.)
   An extensive series of strata, principally developed in the
   Rocky Mountain region, as in the Laramie Mountains, and
   formerly supposed to be of the Tertiary age, but now
   generally regarded as Cretaceous, or of intermediate and
   transitional character. It contains beds of lignite, often
   valuable for coal, and is hence also called the lignitic
   group. See Chart of Geology.
   [1913 Webster]