Locating a Benchmark for a MCDOT Project
It is strongly advised that you check with the client/agency you are working for to determine which benchmark(s), datum, and accuracy they require.
MCDOT uses the following list in order of Benchmark priority:
- NGS Publish Vertical Monument
- NGS Publish Horizontal Monument of A or B order only.
- A Section Corner or Quarter Corner as on the Interactive Map.
- Follow the guide below to access the information.
How to Use the Benchmark Map
- Click on the Land Survey Points (Map) link on the right (or at the bottom if you viewing this page on a mobile device)
- The link will take you to the MCDOT Survey Interactive Map
- When the ArcMap Interactive Map appears you can use search tools to find your area of interest with the Search Tools tab in the upper left corner of the map:
- Your Search Options are then displayed along the left side of the map.
- Once you enter your criteria, select the corresponding [Locate ...] button. The map will then zoom into the area of interest.
- Other common navigating tools are located in the toolbar along the top. These can be used to find your area of interest as well.
- Use the magnifying glass icons to zoom in and out. Use the hand icon to pan across the map.
- You can toggle the map layers by checking them on and off from the 'Layers' tab in the left sidebar.
- To find information on a specific Benchmark use the select tool and click the particular symbol on the map for the Benchmark you are interested in. The map will display a pop-up dialog box similar to this:
- Within the pop-up dialog box, you can view the NGS datasheet for that Benchmark by clicking the appropriate link. The following image is an example of what the NGS Datasheet looks like. It has all of the National Geodetic Survey data for its corresponding monument.
- You can convert the information from NAVD88 or NGVD29 to NAVD88 or NGVD 29 via the NGS Website. Under "tools", select the VERTCON program