About these files

Every outline here begins as public survey data and ends as a file a machine can cut without argument. What happens in between is worth stating plainly, because it affects what the files are good for.

Where the data comes from

Shorelines are taken from the USGS National Hydrography Dataset, the federal inventory of American surface water. It is a work of the United States government and carries no copyright.

Appellation boundaries come from the UC Davis Library American Viticultural Areas project, which digitised the boundary descriptions codified in 27 CFR Part 9 and released the result under an open licence.

What generalisation means

Raw hydrography carries far more detail than any cutting machine can hold. Lake Tahoe arrives with more than eleven thousand points and 179 interior rings, most of them rocks a few metres across. Cut at 300 mm, those rocks are smaller than the beam.

Each outline is therefore simplified against the physical size of the finished piece and the resolution of a typical machine, then checked. Across the California set the median area shifted by 0.007 percent, and the largest shift was under one percent. The shape you cut is the shape of the lake.

Scale

Cutting files ship at three finished widths: 300, 450 and 600 mm, roughly 12, 18 and 24 inches. DXF files carry metric units in their header, so they land at true size in Vectric, Fusion, LightBurn and AutoCAD without being asked. Every record page states the ground distance one millimetre represents.

Layers

Shoreline and islands are separated onto layers named CUT and ISLAND, in red and blue. Most laser and router workflows map a layer or a colour to an operation, so the shore can be cut while the islands are engraved, with no editing.

Licence

A purchase covers personal projects and lets you cut, engrave, print and sell physical items made from the files. It does not cover reselling, sharing or redistributing the digital files themselves, or including them in a bundle or template pack. Redistribution needs an extended licence, which is available on request.

The underlying survey data is public and carries no restriction. The licence covers the prepared files, not the public facts inside them.

What these files are not

They are decorative. Surface areas reflect the water level recorded in the source survey, which is not necessarily full pool, and generalisation moves the shoreline slightly by design. Do not use them for navigation, survey, engineering or legal boundary determination.

Who makes them

Central Coast GIS LLC, a one person geographic information practice in Cambria, California.