Visas for Colombians?

Hello All, I Am an American citizen living in Panama City, Panama. I want ot go on vacation to DR to visit a friend there. My girlfriend is Colombian with CO. pssport. Does she need a visa to enter DR. If so, how do I go about getting her one. I would like to do it by mail if possible. I have searched the web and come up dry. Websites or phone numbers to help me would be much appreciated or even detailed instructions would be better. Thank you so much for any help! Dean