Here is the full list of all 22 Herder achievements.
Explore 3 pastures in one game.
Explore 5 pastures in one game.
Explore 10 pastures in one game.
Own a herd of more than 20 goats.
Own a flock of more than 20 sheep.
Deploy more than 20 landmines in one pasture.
Max out trap inventory.
Reach $1,000 cash.
Reach $5,000 cash.
Reach $10,000 cash.
Reach $15,000 cash.
Reach $20,000 cash.
Vaccinate your flock.
Have a flock of 40 animals.
Have a flock of 60 animals.
Have a flock of 80 animals.
Max out scarecrow inventory.
Collect more than 25 wolf pelts in one session.
Collect more than 25 bear belts in one session.
Collect more than 100 animal pelts in one session.
Use the same Ram or Billy for 4 years.
Regrow your flock of 20 animals after being down to 2.