Is it a federal or state issue?
Federally listed species are under the jurisdiction of the U.S. Fish and Wildlife Service, listed under the Endangered Species Act.  If you have a federal species on-site, you should consult with USFWS through its Missouri office about best management requirements.  All federally listed species are also state listed, but not the other way around.  State listed species are protected under 3 CSR 10-4.111 of the Missouri Wildlife Code.  For all federal and some state listed species, best management practices (BMPs) are available to guide planning. 

Is it known to be on or near the site?
If the letter reports that a species or habitat of concern has been known on or near your site, a first question is whether or not it is actually there at this time.  Some records are several years old, animals range over wide territories, and even plant communities can move over time.  Present on-site conditions can be determined by your personnel, a professional consultant or sometimes by contacting a local MDC Natural History Biologist.  If the species is present, identify follow best management practices.  If BMPs cannot be found in listings on this page, please contact the nearest Conservation Department office or Natural History Biologist for assistance.

Is it simply a possibility on your site?
If the letter reports that project area is located in a region where a species/habitat of concern could be found, further action may not be necessary.  It is, however, a good idea to learn enough about the species/habitat that your site-managers will know to watch for it.  For example, being in a region of Karst geology does not necessitate action by itself.  However, if there is a sinkhole on site, you should take measures to avoid introducing pollutants that could affect groundwater or species dependent on it.