I have converted state highpoint heights to the from NGVD 29 to NAVD 88 data using the USGS Verton calculator.
Interestingly Delaware rather Florida is the big loser in the conversion (the difference in height reflects a 1988 discovery that gravity should have be factored in the 1929 standards for measuring elevations).
Predictably the big mountains all had dramatic increases with Colorado’s Mount Elbert increasing almost 7 feet — it’s conversion was higher than the slightly higher Mount Whitney in California because Whitney is closer to the ocean and thus loses out on the mass calculation.
Read more about the conversion process (and either download the converter or do it online.
The convertor does not calculate Mount McKinley or Mauna Kea because the conversion process is very involved (it is not a clean cut addition to an Excel formula) and the USGS does not have the funding or time to calculate the rest of the U.S. or the world. The look up tables for just the U.S. for the formula are nearly 3 megs!
The table in the second column show current NVGD data rounded to feet, third column shows the heights rounded to feet after the conversion. The fourth column shows the difference in feet after the conversion and the fifth column shows the difference in inches.
| State | NGVD 29 | NAVD 88 | Difference Feet | Difference Inches |
|---|---|---|---|---|
| Alabama | 2407 | 2407 | 0.3 | 3.1 |
| Alaska | 20320 | 20320 | 0.0 | 0.0 |
| Arizona | 12633 | 12637 | 4.4 | 53.0 |
| Arkansas | 2753 | 2753 | 0.2 | 3.0 |
| California | 14494 | 14500 | 6.1 | 73.5 |
| Colorado | 14433 | 14440 | 6.5 | 78.5 |
| Connecticut | 2380 | 2379 | -0.6 | -7.8 |
| Delaware | 448 | 447 | -1.0 | -12.2 |
| Florida | 345 | 345 | -0.2 | -1.9 |
| Georgia | 4784 | 4784 | 0.2 | 2.0 |
| Hawaii | 13796 | 13796 | 0.0 | 0.0 |
| Idaho | 12662 | 12668 | 5.5 | 66.2 |
| Illinois | 1235 | 1235 | -0.2 | -2.3 |
| Indiana | 1257 | 1257 | -0.4 | -5.3 |
| Iowa | 1670 | 1671 | 0.7 | 8.4 |
| Kansas | 4039 | 4041 | 1.6 | 19.2 |
| Kentucky | 4145 | 4145 | -0.3 | -3.2 |
| Louisiana | 535 | 535 | -0.2 | -2.6 |
| Maine | 5267 | 5267 | -0.4 | -4.9 |
| Maryland | 3360 | 3360 | -0.4 | -4.9 |
| Massachusetts | 3491 | 3491 | -0.5 | -5.7 |
| Michigan | 1979 | 1979 | 0.2 | 1.9 |
| Minnesota | 2301 | 2302 | 0.5 | 6.1 |
| Mississippi | 806 | 806 | 0.0 | 0.1 |
| Missouri | 1772 | 1772 | 0.1 | 1.1 |
| Montana | 12799 | 12804 | 5.1 | 61.8 |
| Nebraska | 5424 | 5427 | 2.7 | 32.1 |
| Nevada | 13143 | 13149 | 6.1 | 73.3 |
| New Hampshire | 6288 | 6288 | 0.1 | 0.7 |
| New Jersey | 1803 | 1802 | -0.6 | -6.7 |
| New Mexico | 13161 | 13166 | 5.4 | 64.3 |
| New York | 5344 | 5344 | -0.1 | -1.1 |
| North Carolina | 6684 | 6684 | 0.1 | 1.0 |
| North Dakota | 3506 | 3508 | 1.7 | 21.0 |
| Ohio | 1550 | 1549 | -0.6 | -7.4 |
| Oklahoma | 4973 | 4975 | 2.3 | 27.8 |
| Oregon | 11239 | 11243 | 4.4 | 52.4 |
| Pennsylvania | 3213 | 3213 | -0.3 | -3.6 |
| Rhode Island | 812 | 811 | -0.8 | -9.4 |
| South Carolina | 3560 | 3560 | -0.1 | -1.0 |
| South Dakota | 7242 | 7244 | 2.2 | 26.5 |
| Tennessee | 6643 | 6643 | 0.2 | 2.5 |
| Texas | 8749 | 8751 | 2.2 | 26.8 |
| Utah | 13528 | 13534 | 5.9 | 71.1 |
| Vermont | 4393 | 4393 | -0.1 | -1.8 |
| Virginia | 5729 | 5729 | 0.1 | 1.0 |
| Washington | 14411 | 14417 | 6.3 | 75.7 |
| West Virginia | 4863 | 4863 | -0.2 | -2.9 |
| Wisconsin | 1951 | 1951 | 0.1 | 0.9 |
| Wyoming | 13804 | 13810 | 5.7 | 68.5 |
In posting this one of the helpful links was an online csv to html converter (converting by saving an Excel file to an html table causes problems as Microsoft bloats the conversion). Interestingly this nifty feature has no backwards links at this posting. The site also offers the perl code to run it on your own server.
Highpointers