The site specific documentation that is necessary for the operation and maintenance (O&M) of gas transmission stations are a collection of different vintages, format, quality and credibility. The quality and accuracy of this documentation is critical to the safe, compliant and reliable operation and maintenance of the facilities. This presentation will describe a process to define, understand and quantify the state of these critical documents. It will outline a project that inventoried and assessed critical documents for over 500 gas transmission stations over a two year period. Addressing this issue can seem to be an insurmountable effort, but with structure and dedication, it is possible to resolve. Accurate documentation is foundational to the O&M of a gas facility and allows our crews, engineers and support staff to be successful.