Bridge Heights
The heights listed below are Federal Highway Administration recommendations for vehicle height restrictions on bridges on the Park Loop Road. Taller vehicles should plan their route in advance. Locations are indicated on official park map, which can be downloaded in several formats from the NPS maps website.
Bridge Clearance: Sieur de Monts Area 12'2"
Blackwoods Area 11'8"
Wildwood Stables Area 12'9"
Stanley Brook Road 10'4"
This information is from
http://www.nps.gov/acad/fastfacts.htm#bridge