If you want to get unlimited money cash in the oregon trail game, you must follow some tricks
You have to find the post that is situated at each fort and start the mini-game
After starting the mini game just intentionally lose before it ends.
Usually you will be prompted to play again for a bonus and you have to select ‘No’ when prompted to do so.
By doing so you will now be returned to the fort with $1 for each correct tap that you had previously made.
Always try to keep repeating the process so that you will have a lot of money that you want.