The Bass River Road Net - Late 1832

The towns of Massachusetts were systematically mapped in the early 1830s in response to a state mandate.  Forested and open areas, roads, and significant buildings were identified (although the surveyors and their methods differed somewhat across the state).  Harvard University's Harvard Forest program has created a free online tool that makes it possible to overlay information from these 1830 surveys on a modern USGS topographic map. 

You can access the mapping tool here: 1830 Massachusetts Map Viewing Instructions (but pay attention to caveats - reproduced at the end of this post).  This is easy to use, here I've used it to create a map of Bass River - between Dennis and Yarmouth on Cape Cod - in the early 1830s.  The river appears rather faintly in a modern USGS topo map.  The 1830s roads are superimposed as brown lines, wooded areas in the early 1830s are superimposed as dark green areas:

Bass River in the early 1830s.  Created using the Harvard Forest mapping tool.  Harvard Forest. 2002. 1830 Map Project. Harvard Forest Archives, Petersham, MA. 

Here are some of the things that jump out at me:

• Neither of the two bridges taken over by the county and towns in 1870 were built yet.  The lower bridge would be built in 1832 and the upper bridge would be built in 1833.
• The Harvard map does shows a bridge between South Yarmouth and West Dennis at the place where the lower bridge would be built.  The Harvard map must be stitching together separate maps prepared for Dennis and for Yarmouth.  The original of the Dennis map was produced in 1831 and doesn't show this bridge, although there are marks on the map that may have suggested something near that location.  I haven't seen the complementary Yarmouth map.  I think the analyst has mistaken the a ferry between South Yarmouth and West Dennis for the bridge.  This suggests that the map has to be used carefully.
• The Harvard map does not show a road running north to south, crossing the little creek between Follins Pond and the Mill Pond.  A 1794 map of Yarmouth shows a road at this spot (a small version of this map is printing on page 251 of the Historical Society of Old Yarmouth's book, Images in Time).  Charles F. Swift's reconstruction of the  map of Yarmouth in 1644 also shows this road (History of Old Yarmouth) 
• Several spot checks of forested areas to the east of the river haven't turned up problems with the Harvard map.
• The map shows the location of the first upper bridge, built in 1816.  This is shown where the railroad and Route 6 highway bridges are now, at the southern end of Kelley's Bay.  In 1833 this bridge would be removed and replaced by a new lower bridge where the Highbank Road crosses Bass River now.
• In fact, the map may give a good picture of the area from the fall of 1832 to sometime in 1833.  The lower bridge should have been built by the end of 1832, and the upper bridge wasn't moved to its new location further south until sometime in the second half of 1833.
• The shores of the river and its associated lakes have generally been cleared of woods.
• Many alternative versions of this map, with different features, or smaller scales and more area, could be prepared.  A version showing the area between the town of Barnstable on the west, and Orleans and Chatham on the east, would show the Bass River road net in a larger regional context.

More Bass River links: Bass River.

Here are the Harvard Forest caveats:

However, as with any historical data, the limitations and appropriate uses of these data must be recognized:

1. These maps were originally developed by many different surveyors across the state, with varying levels of effort and accuracy.
2. It is apparent that original mapping did not follow consistent surveying or drafting protocols; for instance, no consistent minimum mapping unit was identified or necessarily consistent among surveyors; as a result, whereas some maps depict only large forest blocks, others also depict small wooded areas, suggesting that numerous smaller woodlands may have gone unmapped in many towns. Surveyors also were apparently not consistent in what they mapped as 'woodlands': comparison with independently collected tax valuation data from the same time period indicates substantial lack of consistency among towns in the relative amounts of 'woodlands', 'unimproved' lands, and 'unimprovable' lands that were mapped as 'woodlands' on the 1830 maps. In some instances, the lack of consistent mapping protocols resulted in substantially different patterns of forest cover being depicted on maps from adjoining towns that may in fact have had relatively similar forest patterns or in woodlands that 'end' at a town boundary.
3. The degree to which these maps represent approximations of 'primary' woodlands (i.e., areas that were never cleared for agriculture during the historical period, but were generally logged for wood products) varies considerably from town to town, depending on whether agricultural land clearing peaked prior to, during, or substantially after 1830.
4. Despite our efforts to accurately geo-reference and digitize these maps, a variety of additional sources of error were introduced in converting the mapped information to electronic data files. Thus, we urge considerable caution in interpreting these maps.

Despite these limitations, the 1830 maps present an incredible wealth of information about land cover patterns and cultural features during the early 19th century, a period that continues to exert strong influence on the natural and cultural landscapes of the region.

Sources: thanks to David Kew and his Cape Cod History website, which contained a link to the Harvard Forest website.

Edits: July 21 - clarification about reading map in second paragraph. "Checks" changed to "spot checks" later on; "forest cover" changed to "woods" in sixth bulleted point.  July 26 - added reference to David Dew's website.  October 4, 2009 - noted missing road between Follins and Mill Ponds.  Deleted reference to location of lower bridge as only problem with the Harvard map.

Comments

[Jesse Mcgraw]

Well, I'm not really surprised that the surveyors who made that map used different methods and that it resulted in a few inconsistencies. The instruments they used were probably not advanced enough to make accurate measurements. They were possibly hired one by one and not as a group with a fixed system. That might explain why the surveyors had varying levels of effort and accuracy, like what was said in the caveats. But all maps have got to start somewhere, right? So we should still give credit to them.