10/26/2025
The concept of trap streets emerged in the early 20th century, with documented use beginning around the 1930s. Mapmakers, seeking to protect their intellectual property, began inserting fictitious streets, towns, or features into their maps. These deliberate errors, known as trap streets, served as a clever watermark: if a competitor’s map included the same fake detail, it was clear evidence of copying.
One of the most famous examples is Agloe, New York, a fictional town created in the 1930s by cartographers Otto G. Lindberg and Ernest Alpers of the General Drafting Company. They formed the name by anagramming their initials and placed it at a remote intersection in upstate New York. To their surprise, Agloe later appeared on other maps and even inspired real-world references, including a general store bearing the name.
Trap streets weren’t limited to roads. Some mapmakers added fake bends in rivers, nonexistent buildings, or altered mountain elevations. The practice was mirrored in other fields, dictionary editors, for instance, inserted fake words called “mountweazels.” Though digital mapping has reduced the need for such tricks, trap streets remain a fascinating chapter in the history of cartography and copyright protection.
