Prerequisites
Install PDAL, Conda instructions worked well under WSL and Mac.
Download (or clone and build) rusty-pullauta.
Lidar data preprocessing
On the USGS data download page, select 'Elevation Source Data' checkbox, then select an extent on the map and click 'Search Products'.
Merging point clouds into a single file
cd data/lidar
pdal -v 0 merge USGS_LPC_*.laz merged.laz
Reproject to UTM and altitude in meters
The following command uses 32617 where the last two digits specify the UTM zone (17). Replace it with the appropriate zone for your area.
pdal translate merged.laz merged_utm.laz reprojection --filters.reprojection.out_srs="EPSG:32617+3855"
UTM zone for your area
USGS data viewer has coordinates widget in the bottom-left corner of the map. It shows 'XY' by default (showing lat-lng) but you can switch it to show UTM. Do not worry about the letter part of the zone.
Run rusty-pullauta
Now run rusty-pullauta on merged_utm.laz file. If it is too large you may want to tile it.
Tiling the data
This will tile you file with some buffer into tiles subfolder.
mkdir tiles
pdal tile merged_utm.laz tiles/tile_#.laz --length 1000 --buffer 50
Add origin flags if you want to align your tiles on 1km grid, for example:
pdal tile merged_utm.laz tiles/tile_#.laz --length 1000 --buffer 50 --origin_x 270000 --origin_y 4705000