Knox County Regional Airport — Rockland, United States

Knox County Regional Airport, known by the code RKD, serves Rockland, Maine, a coastal city known for its lobster industry and maritime heritage. The airport provides essential air service to the midcoast Maine region, including scheduled flights to Boston through the Essential Air Service program, which subsidizes commercial routes to smaller communities. RKD also supports general aviation, seaplane operations nearby, and seasonal traffic tied to Maine's tourism industry, particularly during summer months when visitors flock to the coast. The airport has a single paved runway and modest terminal facilities typical of small regional airports serving rural New England communities that rely on air access for both commerce and connectivity.