Question: What Maine county is Orr's Island in?

Context paragraphs:
Frye Island, Maine: Frye Island is a town in Cumberland County, Maine, United States.  Located in Sebago Lake, the island is accessed via a public car ferry from Raymond Neck, or by private boat.  All residents of the resort town are seasonal.  The majority of property owners hail from New England area states (Maine, Massachusetts, Connecticut, Rhode Island and New Hampshire) however there are many other states also represented on the island.  Frye Island is vacant from November through April, and the ferry does not operate during that time due to the formation of thick ice during cold winter months.  It is part of the Portland–South Portland–Biddeford, Maine Metropolitan Statistical Area.  The town had a population of five at the 2010 census.

Sebascodegan Island: Sebascodegan Island or Great Island is an island at the eastern edge of Casco Bay on the Gulf of Maine.  It is a part of the town of Harpswell with the mainland portion of Harpswell to its west and Orr's Island and Bailey Island to its south.  The town of Brunswick occupies the mainland to the north, and the towns of West Bath and Phippsburg occupy the mainland to the east, across the New Meadows River.

Harpswell, Maine: Harpswell is a town in Cumberland County, Maine, United States, within Casco Bay in the Gulf of Maine.  The population was 4,740 at the 2010 census.  Harpswell is composed of land contiguous with the rest of Cumberland County, called Harpswell Neck, as well as three large islands connected by bridges: Sebascodegan Island (locally known as Great Island), Orr's Island, and Bailey Island and over 200 smaller islands.  Harpswell is part of the Portland–South Portland–Biddeford, Maine Metropolitan Statistical Area.

Bailey Island Bridge: The Bailey Island Bridge (also called the Cribstone Bridge) is a historic bridge in the town of Harpswell within Cumberland County in the state of Maine.

Mount Desert Island: Mount Desert Island (often abbreviated MDI), in Hancock County, Maine, is the largest island off the coast of Maine.  With an area of 108 sqmi it is the 6th largest island in the contiguous United States.  It is the second-largest island on the Eastern seaboard, behind Long Island and ahead of Martha's Vineyard.  According to the 2010 census, the island has a year-round population of 10,615, although it is estimated that two and a half million tourists a year visit Acadia National Park on the island.  The island is home to numerous well-known summer colonies such as Northeast Harbor and Bar Harbor.

Maine State Route 24: State Route 24 (abbreviated SR 24) is part of Maine's system of numbered state highways, running from Bailey Island south of Orr's Island in Harpswell northward to Gardiner, passing through Brunswick along the way.

Annie Haven Thwing: Annie Haven Thwing (July 4, 1851 – June 5, 1940), also known as A.H. Thwing or Anne Haven Thwing, was an American historian and children's author.  Her book for children, "Chicken Little", with illustrations by Nelly Littlehale Umbstaetter, appeared in 1899; as the title suggests, the book re-tells the old story of a chicken who believes the sky is falling.  As an historian Thwing compiled an enormous card index of subjects related to the history of Boston, Massachusetts.  She donated the index to the Massachusetts Historical Society, where the cards "occupied seventy-four library drawers in the catalog room."  She also created a 3-dimensional model of the town of Boston as it appeared in 1775, based on her research.  The model now resides on public display in the Old South Meeting House.  In 1920 her book on Boston history, "The Crooked & Narrow Streets of the Town of Boston 1630-1822", reached the "Boston Globe" best-seller list.  At the time the book sold for five dollars.  In addition to her work on Boston history she wrote about Orr's Island, Maine, where her family maintained a residence.  In the course of her life she corresponded with a number of notables including Oliver Wendell Holmes, Jr., Fanny Bowditch Dixwell Holmes, Alice James, Charles Franklin Thwing, Horace Howard Furness, and Edward Everett Hale.  She also contributed to charitable causes such as the Massachusetts Infant Asylum.

Knox County Regional Airport: Knox County Regional Airport (IATA: RKD, ICAO: KRKD, FAA LID: RKD) is a county owned, public use airport in Knox County, Maine, United States.  It is located three nautical miles (6 km) south of the central business district of Rockland, Maine.  The airport serves the residents of midcoast Maine with commercial and charter aviation services.  Scheduled airline service is subsidized by the Essential Air Service program.  It is also a major hub of freight and mail service to Maine's island communities including Matinicus, North Haven and Vinalhaven.

Great Wass Island: Great Wass Island (approx. 1700 acres) lies in the Atlantic Ocean off the coast of the State of Maine, United States.  On the mainland is Jonesport in Washington County.  The island is 5 mi (8 km) long, 1.5 mi (2.5 km) wide and it is the biggest island in the Great Wass Archipelago, which contains over 43 islands extending off the coast from Jonesport.  Great Wass Island is connected with a bridge to Beals Island, which is then connected to the mainland.  Head Harbor Island and Steels Harbor Island lie close to the east.  The 1450 acre Great Wass Island Preserve is in the island.  The interior of Great Wass Island supports coastal Maine's largest stand of jack pine, other typical plants are bakeapple ("Rubus chamaemorus"), deer-hair sedge ("Trichophorum cespitosum"), and dragon’s mouth orchid ("Arethusa bulbosa").  The island is part of the Town of Beals, in Washington County.

Orr's Island: Orr's Island is an island in Casco Bay and the Gulf of Maine, part of the Atlantic Ocean.  The island is within the town of Harpswell, Maine, U.S., and forms an archipelago with Sebascodegan Island (also known as Great Island) to its north and Bailey Island (reached by the Bailey Island (or Cribstone) Bridge) to its south.

Supporting paragraphs: Orr's Island Bailey Island Bridge
Answer: Cumberland County