upgrade_underground-1.7.1-forge-1.20.1.jar is a release file of the Minecraft mod Upgrade Underground - Caves Overhaul for Forge, made for Minecraft 1.20.1. It was published on August 17, 2026 and is 0.9 MB in size. For the full description, screenshots and every other version, visit the Upgrade Underground - Caves Overhaul mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.
