Extra money:

Type more money to receive $400. Note: This may only be done once per game.

Advance to Oregon:

When choosing to go by road or river, select the river. Click the Left Mouse Button when starting to advance to the next segment. Repeatedly click to reach Oregon.

Skip to Oregon:

When you get to decide to take the road or the river, take the river. When you start, just click. You should skip to the next segment. Just keep clicking until you get to Oregon