USGS Beaver Island topographic map, 1956

Summary

The held 1956 USGS Beaver Island 15-minute quadrangle is a 1:62,500 topographic-map snapshot of most of Beaver Island and High Island. The sheet represents topography from 1954 aerial photographs, field checked in 1956, and hydrography compiled from 1955 Lake Survey charts.

It visibly labels St. James, Peaine, High Island, Lake Geneserath, Font Lake, and many roads, waters, contours, and state-forest areas. These are cartographic attestations on this edition; they supply a useful mid-century comparison layer for earlier maps and later geographic records.

Three dates on one sheet

The edition is dated 1956, and nothing on it is uniformly 1956. The sheet’s own statements put topography from 1954 aerial photography, a field check in 1956, and hydrography compiled from 1955 Lake Survey charts — three different observation regimes, printed together, distinguishable only by knowing which layer a feature belongs to.

That matters whenever this sheet is used to date something. A road drawn here was photographed in 1954 and confirmed on the ground in 1956, so its absence from an earlier map and presence here brackets it loosely at best. A depth or a shoreline belongs to the hydrographic layer and inherits the Lake Survey’s own dates and datum, which are not the topographic ones — and, as the Lake Survey sheets in this archive state explicitly, a charted shoreline is the water surface at the time of that survey rather than a fixed coast.

This is the same caution the 1907 and 1911 charts require, in a different form. A published map is a compilation with an issue date, and the issue date is the one thing on it that certainly does not describe any feature.

What it is good for

Read with those limits, the sheet is one of the more useful mid-century layers the archive holds. It is the last full topographic treatment of the island before the 1986 provisional 1:24,000 series, it carries interior detail — contours, inland lakes, forest land and the road network — that no chart does, and being georeferenced from its own embedded transform it can be laid directly under modern data without a registration step of this project’s own devising. Where it disagrees with the 1986 sheet, the disagreement is evidence about thirty years of change rather than about either sheet’s accuracy.

Georeferencing, and what it says about the sheet

The held PDF is a TerraGo GeoPDF: it carries its own transform in an embedded LGIDict, so the sheet can be registered to ground coordinates without picking a single control point. This archive did that (scripts/georeference_topo.py), and the resulting record states the sheet’s own terms:

Three consequences follow, and each one is a way of getting a comparison wrong.

The datum is NAD27, not NAD83 or WGS84. A position read off this sheet and plotted on modern data lands tens of metres from where it belongs unless it is shifted. That is the same order as the difference this archive has had to allow for when testing 1986 ink coverage against walked GPS.

The projection is polyconic, which no modern layer here uses — the working CRS is EPSG:3078. Polyconic is one of only three projections among the 22 georeferenced quads in this collection (six polyconic, fifteen transverse Mercator, one Lambert conformal conic), and it is the signature of the 1955–56 1:62,500 series specifically.

It does not cover the whole island. The coverage check puts the sheet over 78% of the island area, which is why the summary above says most of Beaver Island. A feature’s absence from this sheet may mean it was off the sheet.

Evidence and limits

This map establishes what the USGS printed and depicted on this dated edition. It does not establish legal township or parcel boundaries, ownership, public access, a road’s maintenance or condition, a building’s construction or use, a population, or the exact date a mapped feature began or ended. A label or symbol must be independently checked before it supports a detailed historical claim.

The aerial-photography and field-check dates describe the map’s compilation, not a uniform observation date for every feature. Hydrographic detail also has its own stated 1955 chart source.

The page

Rendered from the held scan.

Added 2 August 2026 · revised 4 August 2026. Recent changes