From the south:

The fastest approach from the south is via I-95 North through northeastern Massachusetts, seacoast New Hampshire, and southern Maine. Take I-295 through the Portland area; I-295 rejoins I-95 north of Portland. Continue on I-95 North to I-395 at Bangor (1 hour from Bar Harbor). Follow I-395 about 5 miles to Rt. 1A. Take 1A to Ellsworth. At Ellsworth Rt. 1A becomes Rt. 3 East. At this point you will begin seeing large, clear signs indicating the route towards Bar Harbor.

From Northern New Hampshire (Conway):

Take Rt. 302 east to Rt. 11. Take Rt. 11 northeast to Rt. 26. Take Rt. 26 south to Rt. 122. Take Rt. 122 east to I-95, Proceed north towards Bangor and follow the route described above.

A more scenic route: Take Rt. 16 north to Gorham then follow Rt. 2 east. At Newport, ME take I-95 north towards Bangor then follow the directions above.

From Bangor International Airport:

Ask the car rental agent for directions to I-395. Take I-395 in the direction of Ellsworth/Bar Harbor and follow the directions above "From the South" from that point onward.

Approaching Mt. Desert Island:

After passing the Bar Harbor Airport on the left hand side and Trenton Bridge Lobster Pound on the right hand side you will cross a small bridge and causeway onto Mt. Desert Island. About 8 miles after crossing the bridge you will pass the Hulls Cove entrance to Acadia National Park. 2.6 miles beyond the park entrance you will come to a stop sign at the junction of Rt. 3 and Rt. 233; turn left (staying on Rt. 3). Take the first left onto Holland Avenue (the Aurora Inn, a small white motel, is on the near left side of the intersection of Holland Avenue). The Graycote will be the large gray house four doors down Holland Avenue on the right. Parking is on the left side of the house.
 

Some driving times to Bar Harbor:
 

Airports:
Driving times to the Graycote. Inn