When I was in my mid-twenties and learning the honorable profession of land surveying, I was lucky to be guided by a mentor who would grab a book off his office shelf and say, “Every surveyor should have a copy of this!” The first example he waved at me was Davis, Foote and Kelly’s Surveying: Theory and Practice (1966), which I acquired. Over time I formed my own collection of “must-have” surveying books. Those now number about twenty–a small count. Of those twenty, a third are essential texts. That’s six or seven books–and through the years they have counseled me whenever I encounter a unique or difficult situation. Like all good books, they’ve become friends. The publication of those books spans one hundred years. The first modern “essential text” in my pantheon is Mulford’s Boundaries and Landmarks (1912). The last book I added was Chris Lucas’ The Pincushion Effect (2011). Note that this works out to twenty books published over a hundred years that are important to surveyors–an average of one book every five years. If we apply this same logic to the publication of what I consider essential texts, these rare books appear on average every fourteen years. Another addition to my essential collection occurred in 2017 with the publication of Donald Wilson’s Boundary Retracement: Processes and Procedures. Of course the mere publication of a book about surveying is rare. It’s rarer still when that book is an essential text. Our field can justifiably celebrate Wilson’s Boundary Retracement. It promises to become the book you smugly bring under your arm to court, the book you wave when the judge asks you to justify a disputed call. It promises to serve as the surrogate bible that state boards of registration should publish, and never do. I’m setting a high bar, and Wilson meets it. Wilson has been in practice for more than fifty years, and teaches at the University of New Hampshire. He is the author or co-author of a half dozen must-have books on this topic, and has conducted seminars around the country. He and Walter Robillard are best known as the co-authors of the last edition of Evidence and Procedures for Boundary Location (2006). In reality, Wilson’s 2017 Boundary Retracement is an expansion and refinement of his seminal works with Robillard. In his new book Wilson exclusively covers retracement. Wilson emphasizes that retracement is not surveying a deed, but following in the footsteps of the original surveyor. As the author asserts, this is a principle that is misunderstood by many, and of those familiar with the principle, many more lack the “training and experience” to implement it correctly. Wilson reminds us that a property deed is intended to reflect the original survey, and not the other way around. For instance, an original surveyor creates new property bounds, attempts to locate them accurately and prepares a plan representing those physical bounds as located. Yet that original surveyor’s measurements reflect inherent equipment and techniquedriven errors. The surveyor may measure a distance between two monuments at 202.25 feet, whereas the precise physical distance is 202.385 feet. Yet a deed is then created from the surveyor’s plan. Even though the physical bounds exist, the deed distance call for that line is 202.25 feet, reflecting a measurement error of 0.135. The classic “deed surveyor” surveys deed calls rather than the physical evidence, setting a “correct” corner based on the deed rather than original corners. The resulting “correct” corner is in fact incorrect, often worsening the errors made by the original surveyor. By law the original physical corners prevail, but are frequently ignored by a surveyor who aspires to greater accuracy (while neglecting legal duties). A deed survey is not a retracement, but an inexact copy. It’s close, but it’s wrong. This errant survey practice creates what we call the pincushion effect, something seen across the country. Lucas’ The Pincushion Effect devotes some 350 pages to this single problem. (In fact, just this last year in my own practice, I set original corners in a subdivision and was amused, to be polite, to find within a few months new corners set on several lots within a half inch of my rebar or PK nails.) The release of Boundary Retracement could not come at a better time. Wilson is thorough as he covers the topic. After the book defines the principles of retracement, Wilson continues with land title definitions and many related topics, including prescription, ambiguities and intent. An entire chapter covers corners and lines (Wilson defines over 20 types of corners alone). He discusses protracted boundaries at great length. A key chapter discusses “Which Set of Footsteps is Which?” Because identifying the original surveyor’s work often becomes a forensic exercise, many portions of Boundary Retracement complement Wilson’s earlier Forensic Procedures (2008). Other chapters in Boundary Retracement examine errors and how to reconcile them; evidence and how to recognize it; and boundary agreements. After laying this extensive background, Wilson segues into an invaluable discussion about procedures, and asks what makes an effective retracement surveyor. He defines good practice and does so within a framework defined by numerous court decisions. Court cases examined throughout the book follow Wilson’s usual method of outlining salient claims in each case, then documenting evidence and testimony that points toward a court’s final decision. In a unique contribution to this subject, Wilson includes an appendix of almost thirty pages of court decisions, listed by state. I remain amazed at the amount of effort that went into this compilation alone. Boundary Retracement ends by covering lost and obliterated corners, parol evidence, nonfederal rectangular surveys, longlots, military grants, and special and overlapping grants. He ends the book with a final chapter on forensic applications, which include historical research and investigative tools. A secondary appendix also includes a unique Table of Authorities, which is an alphabetized list of the numerous cases he cites. In summary, Boundary Retracement is one of the most important surveying books published in the last decade. It deserves to be on every practicing surveyor’s bookshelf. I’m sure that my old mentor would have waved this book at me and said, “Every surveyor should have a copy of this!” Whether you are just beginning in the survey profession, or have many years of boundary experience, Wilson’s expertise enlightens beginners and pros alike. For any SIT, this is a must-have text; for any professional surveyor who may be rusty when a controversial boundary survey comes along, this book is the one you turn to for a best procedures review. And for any surveyor who enjoys an in-depth look at boundary principles that underlie the survey profession, Boundary Retracement: Processes and Procedures is an exemplary read. If Wilson’s book is not already on your shelf, you do yourself and your profession a disservice. The book is available in either hardcover or as an e-book through Amazon and other booksellers. A direct link to the publisher’s website follows: https://www.crcpress.com/Boundary-RetracementProcesses-and-Procedures/Wilson/p/book/9781498727105 Patrick C. Garner is a Professional Land Surveyor in Massachusetts who has been in private practice for more than 40 years. A Principal of Patrick C. Garner Company Inc., he frequently conducts technical seminars, provides peer reviews for cities and towns, and works as an expert witness in Massachusetts courts. He also provides 20 on-line continuing education courses through RedVector, many of which focus on legal issues in land surveying.