Halfmile used to maintain free maps, compiled from public sources and updated by hikers, for hikers. There’s a decent amount of work needed to keep these current. For a number of reasons, they’re no longer being updated.
The new NatGeo maps are nicer, waterproof, and their purchase helps fund the PCT. Something you should do anyway.
Do me a favor and buy them with this link, Amazon gives me a few pennies which help defray the costs of running this service. For hikers with people following along at home, consider a nice PCT wall map with some arrow post-it stickers to track your progress.
If you want to roll the dice with old maps, I’ve archived them here as zip files. WARNING: THESE ARE OLD. I MAKE NO WARRANTY AS TO THEIR SUITABILITY FOR YOUR PURPOSE. I RESERVE THE RIGHT TO TAKE THESE DOWN AT ANY TIME. KNOW WHAT YOU ARE DOING. DONT GET LOST OR DIE. YOU HAVE BEEN WARNED.