A letter is nice, but that doesn't protect shareholder equity - ie, if mgmt says "We understand your frustration, but this is an event affecting all junior miners, not just PRB," then don't bother.
What is needed is a letter telling shareholders what mgmt is going to do, ie highlight PRB's resources in public forums (ads in major shareholder pubs). In addition, since PRB gets no credit from analysts for the chromite, this asset needs to be spun off.
WB