Travaling TDP what denominations of U.S. cash to bring

Much better to bring Pesos chilenos

In the park if you pay with dollars you may not need to pay the tax, carry $20s.

I agree at times the tax can be avoided, However I gotta say as nahuel put it, Chileans use pesos. I doubt anyone is gonna have your change in USD and your counting on someone knowing and using the current exchange rate for your charges and change. With the dollar in the shitter these days, people aren't going to treat it like before. Your ATMs only dispense Chilean pesos as well. It's not like Bolivia where you can get dollars or Bolivianos, the local currency from ATMs. As a general rule, you are usually far better off using local currency for purchases whatever the country. It's the when in Rome scenario. In the past there was more reason to carry USD as there were far fewer ATMs, the dollar was more stable and you would at times wonder if the country would devalue it's currency overnight and stiff you. Chile's economy is very strong now days. I have not been in the area in recent years, and don't know if the refugios accept credit cards. I expect the expensive hotels do. In the states, some Wells Fargo offices carry foreign currency if you desire time to get some local currency and figure out what it's worth. You'll feel like a rich man carrying around 10,000 peso notes.