Looking for minimum and maximum elevation for US counties

Question

Where can I find minimum and maximum elevation data for US counties?

It would be a bonus if I could directly access it from within R, but other solutions are also good.

Answer 1

Use {geodata} package for elevation and boundaries, then use terra::zonal or terra::extract to get the min/max values, like:

elev <- geodata::elevation_30s("USA", path = "data")
usa <- geodata::gadm("USA", path = "data")

usa$NAME_1 |>
  as.data.frame() |>
  dplyr::mutate(max = terra::zonal(elev, usa, fun = "max", na.rm = TRUE))
#>              usa$NAME_1 USA_elv_msk
#> 1               Alabama         689
#> 2                Alaska         NaN
#> 3               Arizona        3709
[...]
#> 51              Wyoming        4032

There are missing values for Alaska and Hawaii because USA in elevation_30s data set is filtered to mainland:

terra::plot(elev)

You can use geodata::elevation_global() to get global coverage and extract data.

^{Created on 2024-08-28 with reprex v2.1.0}