The official money is the Costa Rica Colones (Fluctuating around 420 - 700 colones per $1 USD. The US Dollar is widely accepted in Costa Rica, so exchanging US Dollars to Costa Rica Colones is not necessary. Smaller denominations of $20 or less are easiest to cash. Visa and Mastercard are also widely accepted. AMEX and DISCOVERY slightly less accepted.
ATMS: There are ATMS within driving distance. Some only accepts Visa and most will dispense money in both colones & USD.