Sure. The radios are inexpensive ESP32 LoRa dev boards (with good antennae and 3D printed enclosures), and the software is a modified version of Meshtastic. This is the article that inspired me -- I think that will lead you to more detail about what I did than I can give here.

https://hackaday.com/2020/02/26/lora-mesh-network-with-off-t...

These perform better than the Baofeng radios we used before, but the terrain is still a limiting factor.