From Chalatenango, hop on bus no. 125 and ask the driver to let you off at Amayo, where you can catch bus no. 119 to the center of La Palma. The trip takes about 1 hour and 15 minutes. You can reach Chalatenango in just over 2 hours from San Salvador on bus no. 125.
La Palma is just off Hwy. CA-4, which is the country's main north-south highway. Just drive north a little less than 1 hour from Chaletenango and about 1 1/2 hours from San Salvador, and follow the signs. If you reach the Honduran border, you've gone a few miles too far.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.