Question: Which subrange of the Appalachian Mountains was added to the National Register of Historic Places?
Context: The Noah "Bud" Ogle Place was a homestead located in the Great Smoky Mountains of Sevier County, in the U.S. state of Tennessee.  The homestead presently consists of a cabin, barn, and tub mill built by mountain farmer Noah "Bud" Ogle (1863–1913) in the late 19th century.  In 1977, the homestead was added to the National Register of Historic Places and is currently maintained by the Great Smoky Mountains National Park. The "Old National Pike Milestones" marked each mile of the old National Road in Maryland, an eastern coastal state of the United States, from its dominating city of Baltimore to major towns of western Maryland, as Frederick, and between it and Hagerstown, to Hancock, through to Cumberland in the western panhandle of the state in the foothills of the Appalachian Mountains.  The surviving stones have been included in the "National Register of Historic Places", maintained by the National Park Service of the U.S. Department of the Interior, and may be seen along the route variously designated as U.S. Route 40, Maryland Route 144, Alternate U.S. Route 40, and several other roads that trace the path of the original "Old National Pike".  From Baltimore to Cumberland, the road was surveyed and laid out with construction in several phases over different periods of time by several turnpike companies, chartered by the General Assembly of Maryland beginning in 1808.  Earlier in 1806, the United States Congress with the approval of third President Thomas Jefferson, authorized the surveying and further construction of a "national road" to continue on from Cumberland on the upstream of the Potomac River further to the west across additional mountainous ranges in the Allegheny Mountains to the newly admitted State of Ohio (admitted 1803 as the seventeenth state).  Later the congressional action was amended to direct the road to the state boundaries on the Ohio River and it eventually landed at Wheeling, Virginia.  In later decades, the road was extended west across Ohio, Indiana and into the Illinois Country, to eventually terminate by the 1840s in Vandalia, the territorial capital of Illinois, just east of the Mississippi River, and northeast of the newly emergent, frontier river port metropolis of St. Louis of the Missouri Territory and the former Louisiana Purchase of 1803 to the west. The Robert G. Griffith Sr.  House is a historic house near Summit, Blount County, Alabama.  The two-story I-house was built in 1851 for Robert Griffin Griffith.  As the only surviving early I-house in Blount County, the dwelling is representative of the residence of a financially comfortable agricultural family in the Appalachian region of Alabama.  It was added to the Alabama Register of Landmarks and Heritage on June 30, 1995 and to the National Register of Historic Places on March 14, 2000. Pamela Cunningham Copeland (May 5, 1906 – January 25, 2001) was an American award-winning horticulturist and historical preservationist, known for her philanthropy.  Her home and gardens became Mt. Cuba Center, a public garden and research center for Appalachian Piedmont flora that was added to the National Register of Historic Places in 2003. The Tannehill Ironworks is the central feature of Tannehill Ironworks Historical State Park near the unincorporated town of McCalla in Tuscaloosa County, Alabama.  Listed on the National Register of Historic Places as Tannehill Furnace, it was a major supplier of iron for Confederate ordnance.  Remains of the old furnaces are located 12 mi south of Bessemer off Interstate 59/Interstate 20 near the southern end of the Appalachian Mountains.  The 2063 acre park includes the John Wesley Hall Grist Mill, May Plantation Cotton Gin House, and the Iron & Steel Museum of Alabama. Sam A. Baker State Park is a state-owned, public recreation area encompassing 5323 acre in the Saint Francois Mountains region of the Missouri Ozarks.  The state park was acquired in 1926 and is named for Missouri governor Sam Aaron Baker who encouraged the development of the park in his home county.  In the 1930s, the Civilian Conservation Corps added many structures to the park including the park office and visitors center, which was originally used as a stable, the stone dining lodge, most of the park's cabins, and the backpacking shelters on the Mudlick Trail.  Twenty-five buildings and five structures comprise the Sam A. Baker State Park Historic District, a national historic district listed on the National Register of Historic Places in 1985. Traveler's Rest was a stopping point of the Lewis and Clark Expedition, located about one mile south of Lolo, Montana.  The expedition stopped from September 9 to September 11, 1805, before crossing the Bitterroot Mountains, and again on the return trip from June 30 to July 3, 1806.  Traveler's Rest is at the eastern end of the Lolo Trail.  It was declared a National Historic Landmark in 1960 and added to the National Register of Historic Places in 1966.  The boundaries were subsequently revised, and mostly lie within the 51 acre Traveler's Rest State Park, which is operated by the Montana Fish, Wildlife & Parks.  Significant archeological findings made in 2002, including latrine sites with traces of mercury and fire hearths, make this the only site on the Lewis and Clark National Historic Trail that has yielded physical proof of the explorers' presence.  Records made by Lewis and Clark often spell "Traveler's" as "Traveller's".  This spot is largely unchanged from the days of Lewis and Clark.  From this location, Lewis and Clark split up to explore Montana during their return trip, not reuniting until they reached Sanish, North Dakota. The Great Smoky Mountains are a mountain range rising along the Tennessee–North Carolina border in the southeastern United States.  They are a subrange of the Appalachian Mountains, and form part of the Blue Ridge Physiographic Province.  The range is sometimes called the Smoky Mountains and the name is commonly shortened to the Smokies.  The Great Smokies are best known as the home of the Great Smoky Mountains National Park, which protects most of the range.  The park was established in 1934, and, with over 9 million visits per year, it is the most-visited national park in the United States. The Gunsight Pass Shelter in Glacier National Park is a rustic stone building near the treeline.  The one-room shelter is equipped with a woodstove.  Work began on the shelter in September 1931 and was complete in June 1932 to a design by the National Park Service Landscape Division.  The design was inspired by similar cabins built by the Appalachian Mountain Club in the White Mountains of New Hampshire.  The shelter is located on the South Loop Trail, itself listed on the National Register of Historic Places. The John Messer Barn is a historic structure within the Great Smoky Mountains National Park in Sevier County, Tennessee, United States.  Located along the Porters Creek Trail in the Greenbrier valley, it was constructed in 1875 by Pinkney Whaley.  The Whaleys later sold their farm to John H. Messer, who was married to Pinkney's cousin, Lucy.  In the 1930s, the Smoky Mountain Hiking Club, which constructed the Smoky Mountain Hiking Club Cabin nearby, leased the barn from the National Park Service.  The barn was added to the National Register of Historic Places in 1976, and is the last surviving structure from the pre-park Greenbrier Cove community.  This barn should not be confused with the Messer Barn in Cataloochee, which was built by John's cousin, Will Messer.
Answer: Great Smoky Mountains