Find a stranger that needs your help. It will say "Save the treasure hunter". After that, loot the bodies of the bandits that killed the treasure hunter. You will get the first treasure map. Note: Each treasure comes with the map to the next treasure.

New Austin Territory
Treasure #1: This treasure is at "Hanging Rock". Go to the base of the largest boulder and walk around it until you reach the treasure.
Treasure #2: This treasure is east of "Rio Bravo". It is at the end of the Rio del Lobo horse path. Follow the path to the treasure.
Treasure #3: This treasure is in the old mansion in "Umbleweed". Go to the basement and search underneath the skull that is hanging on the wall.

Mexico Territory
Treasure #4: This tresure is north of "Chuparosa" Find the tree of skulls and travel towards the river to the second stone wall.
Treasure #5: This treasure is in "Puerto Cuchillo" northeast of Escalera. Climb to the top of the rock formation for the treasure. Note: After this treasure, stagecoach rides will be free.
Treasure #6: This treasure is on the left of the giant rock arch located south of "Chuparosa"
Treasure #7: This Treasure is northeast of "Chuparosa" Follow the path (to the left of the rock fingers) to the treasure.

The Northern Territory
Treasure #8: This treasure is east of your ranch at Beecher's Hope. Find the large tree that is split down the middle. Walk north of the tree in the first gap of the stone fence.
Treasure #9: This is the last treasure. It is in the snowy mountains north of "Tall Trees" Take the horse path north of Mansinita Post until you reach a clearing. Go north and find a small cave on the side of the mountain. The treasure is on the right. Note: After this treasure you will receive the Treasure Hunter's Satchel, which holds twice as many items as a normal satchel.