Question: Within which mountains European settlers found gaps in the mountains?

Context paragraphs:
Transportation in Appalachia: Appalachia's geography presents special challenges to transportation.  In Europe, while mountain ranges presented challenges to transport, they could mostly be avoided.  In North America, however, the Appalachian Mountains presented a barrier that could not be easily out-flanked.  Initially, European settlers found gaps in the mountains, among them the Cumberland Gap and the Wilderness Road.

1813 crossing of the Blue Mountains: The 1813 crossing of the Blue Mountains was the expedition led by Gregory Blaxland, William Lawson and William Charles Wentworth, which became the first successful crossing of the Blue Mountains in New South Wales by European settlers.  The crossing enabled the settlers to access and use the land west of the mountains for farming, and made possible the establishment of Australia's first inland settlement at Bathurst.

Mswati II: Mswati II (c. 1820–1868), also known as Mswati and Mavuso III, was the king of Swaziland between 1840 and 1868.  He was also the eponym of Swaziland.  Mswati is considered to be one of the greatest fighting kings of Swaziland.  Under his kingship, the territorial boundaries of Swaziland were greatly increased.  Mswati was the son of Sobhuza I and Tsandzile Ndwandwe (known as 'LaZidze) who after ruling as Queen Mother became Queen Regent after the death of her son.  After the death of Sobhuza, Mswati inherited an area which extended as far as present day Barberton in the north and included the Nomahasha district in the Portuguese territory of Mozambique.  Mswati’s military power initially suppressed by infighting with his brothers Fokoti, Somcuba and Malambule was increased in the late 1850s and later on.  When Mswati's armies attacked organized forces of other Bantu tribes or nations, the goal was initially plunder in the form of cattle and captives, rather than incorporation into one political unit.  The arrival of Trekboers in what would become the Transvaal republic marked the first contact with Swazis and European settlers occurred during this period.  Mswati greatly extended the boundaries of the Swazi territory beyond that of the present state with military outposts and royal villages outposts such as Mbhuleni, on the upper Komati River at the foot of the Mkongomo Mountains, south of Badplaas, Mekemeke which is east of the Mbayiyane Mountains, situated east of Mantibovu (Low’s Creek).  The death of Mswati II in July 1868 ended the era of Swazi conquest, territorial expansion and resulted in unification of various people into one nation.

Greenland, Arkansas: Greenland is a city in Washington County, Arkansas.  The community is located in the Boston Mountains deep in the Ozark Mountains.  Early settlers found prosperity by growing fruit, including apples and a variety of berries, and raising chickens.  The completion of the St. Louis–San Francisco Railway through the mountains in 1882 further grew the local economy, leading Greenland to incorporate in 1910.  Located immediately south of Fayetteville in the Northwest Arkansas metropolitan statistical area, Greenland has been experiencing a population boom in recent years, as indicated by a 39% growth in population between the 2000 and 2010 censuses.

Piedmont National Wildlife Refuge: Piedmont National Wildlife Refuge is a 35000 acre National Wildlife Refuge established in 1939 and located in central Georgia.  It is primarily an upland forest dominated by loblolly pine on the ridges with hardwoods found along the creek bottoms and in scattered upland coves. Clear streams and beaver ponds provide ideal wetland habitat for wood ducks and other wetland dependent species.  In the early 19th century the European settlers arrived in abundance and began to clear the land to plant a variety of crops.  The settlers removed more than 90% of the forest.  The continuous planting of cotton caused serious erosion and soil infertility.  By the late 1870s they had abandoned more than a third of the land because the land could not sustain crops.

Culture of Arkansas: The Culture of Arkansas is a subculture of the Southern United States that has come from blending heavy amounts of various European settlers culture with the culture of African slaves and Native Americans.  Southern culture remains prominent in the rural Arkansas delta and south Arkansas.  The Ozark Mountains and the Ouachita Mountains retain their historical mount.  Arkansans share a history with the other Southern States that includes the institution of slavery, the American Civil War, Reconstruction, Jim Crow laws, segregation, the Great Depression, and the Civil Rights Movement.

Sauratown Mountains: The Sauratown Mountains,( Pronounced Sar-a -town like Laura not Sour )which are sometimes called "the mountains away from the mountains", are an isolated mountain range located within Stokes and Surry counties in the U.S. state of North Carolina.  The vast majority of the range is located in Stokes County, and even though the range occupies only 5% of Stokes County's area, it dominates the county's scenery from almost every direction.  The Sauras rise sharply 800 to 1,700 feet (244 to 518 meters) above the surrounding terrain.  The Sauratown Mountains were named after the "Sauras", a Native American tribe that lived in the area before European settlers arrived in the early 1700s.  The range consists of rugged, heavily forested ridges frequently broken by large quartzite rock cliffs that can be seen for miles.  The Sauratown Mountains are known for offering some of the best rock climbing in North Carolina.  The highest point in the Sauratown Mountains is Moore's Knob, which rises to 2,579 feet (786 m).

Chetzemoka: Cheech-Ma-Ham (Chetzemoka).  In 1808, a child was born at KaTai to Quah-Tum-A-Low and Lach-Ka-Nam, chief of the S’Klallam.  He was named Cheech-Ma-Ham (or Chits-Ma-Han).  Cheech-Ma-Ham was forty years old when the first white settlers arrived at Port Townsend, Washington.  The settlers found his name difficult to pronounce so they changed it to Chetzemoka; and he was; given the “royal” nickname Duke of York.  His son was called Prince of Wales and his two wives were Queen Victoria and Jenny Lind.  His older brother, next in line to become chief, was called King George.  King George was the quarrelsome type, unlike the diplomatic Duke.  One day, after a disagreement, he packed up all his possessions and paddled off to board a ship for San Francisco, never to return.

Tyson McCarter Place: The Tyson McCarter Place was a homestead located in the Great Smoky Mountains of Sevier County, in the U.S. state of Tennessee.  Before the establishment of the Great Smoky Mountains National Park in the 1930s, the homestead belonged to mountain farmer Jacob Tyson McCarter (1878–1950), a descendant of some of the area's earliest European settlers.  While McCarter's house is no longer standing, several outbuildings— including a barn, springhouse, corn crib, and smokehouse— have survived, and have been placed on the National Register of Historic Places.

Cumberland Gap: The Cumberland Gap is a narrow pass through the long ridge of the Cumberland Mountains, within the Appalachian Mountains, near the junction of the U.S. states of Kentucky, Virginia, and Tennessee.

Supporting paragraphs: Transportation in Appalachia Cumberland Gap
Answer: Appalachian Mountains