Hi Patti,
It is so exciting that you are planning on visiting the area your ancestors were from! I'd love to help you find a way to travel there without renting a car.
From the Busáras (bus station) in Dublin you can hop on Bus Éireann
line 32 to Letterkenny, which will take you there in 4 hours. From the Letterkenny you can take
service 974 directly to Carrigart, which will take around 40 minutes.
Once you get to Carrigart there are several taxi services that can pick you up and take you wherever you need to go. Take a look at the options below:
McCarrons Taxis TEL: + 353-87-6294260
McGeever Taxis/Mini-bus TEL: + 353-85-1663687
McGinley Taxis TEL: + 353-87-6555443
Mevagh Taxis & Minibus Hire TEL: + 353-74-9155512
Mulroy Taxis TEL: + 353-87-2299901
I hope this was helpful, and please let me know if you have any questions! :)