Get Pesos Before You Visit Loreto, Mexico
You WILL need pesos for many restaurants, taxis, and smaller shops. Grocery stores, markets, and many restaurants will accept cards, but some may add a small fee.
Your bank can exchange dollars for pesos before your trip. It can be nice to have a some pesos when you first land, but ATMs are common and usually offer much better exchange rates than your bank. Avoid walk-up currency exchanges at all costs! It's a lot easier to pay for stuff in pesos rather than dollars, which are usually accepted at 10% below market rate.
Wells Fargo will exchange pesos for you, taking about 5% compared to the current exchange rate. For example, if the exchange rate is 20 to 1 and you gave them $1000, you will get back about 19,000 Pesos or $950 worth of Pesos. Yes, 5% is a lot, but it's better than the exchange rate each individual store/person will give you (~10%). Also, it is a lot easier to count in reason about how much things cost if you use pesos.
There is an ATM in the Airport, but like all ATMs, it might not work when you need it, so don't rely on it for your taxi ride!
From 2015 to 2021 the Peso has been between 15-20 to 1.