Lake Chapala, like most of Mexico, is a cash society that does not accept US dollars and very few credit or debit cards. Most people withdraw cash from ATMs. There are several to choose from, just keep in mind there is a daily withdrawal limit of $10,000 MXN pesos. Some ATMs have a limit of $5,000 MXN pesos per daily withdrawal. Cash can also be withdrawn from Mexican or International banks.  The withdrawal bank fees range from bank to bank, but the average being around $35 MXN pesos. Exchange rates are easily checked with any of the online currency converters.