Question: The Silent Valley Reservoir is located in a granite mountain range named after a Gaelic Clann named what ?

Context paragraphs:
McDowell Mountains: The McDowell Mountain Range (Yavapai: Wi:kajasa) is located about twenty miles north-east of downtown Phoenix, Arizona, and may be seen from most places throughout the city.  The range is composed of miocene deposits left nearly five million years ago.  The McDowells share borders with the cities of Fountain Hills, Scottsdale, and Maricopa County.  The city of Scottsdale has made its share of the McDowells a preserve, and has set up a wide trail network in partnership with the McDowell Sonoran Conservancy.  The McDowell Sonoran Conservancy was established in 1991.  The highest peak in the McDowells is East End, at 4,069 ft .  This mountain range also serves as a sacred marker to the Yavapai people.  The boundaries of the range are generally defined by Saddleback Mountain in the South and Granite Mountain as the Northern boundary.  The McDowells also comprise popular landmarks such as Pinnacle Peak and Tom's Thumb.  Although technically a stand-alone, Mt. McDowell (referred to as Red Mountain by Phoenix residents), not to be confused with McDowell Peak, is sometimes listed on maps as a part of the McDowell Mountains.

Binnian Tunnel: The Binnian Tunnel (2.5 miles long) was constructed between 1947 and 1950/51 and is located under the Mourne Mountains in County Down, Northern Ireland.  The main purpose of the tunnel is to divert water from the Annalong Valley to the Silent Valley Reservoir underneath a number of mountains including Slieve Binnian, after which the tunnel was named.

Granite Mountain (Arizona): Granite Mountain (Yavapai: ʼWi:kvte:wa ) is a 7,628 ft mountain located in Yavapai County, Arizona that covers roughly 12 square miles (31 km).  It was once known as Mount Gurley, for the first governor of the Arizona Territory, John A. Gurley.  Its southwest face has a sheer granite cliff approximately 500 feet (150 m) high that is one of the best locations for rock climbing in the state of Arizona.  It is located in the Granite Mountain Wilderness, which is managed as a part of the Prescott National Forest.  The mountain stands at the northern end of the Sierra Prietas, and borders Skull Valley on the west, on the northwest by the Santa Maria Mountains, and east by the Williamson Valley.

Slieve Binnian: Slieve Binnian (from Irish: "Sliabh Binneáin" , meaning "mountain of the little peak" ) is one of the Mourne Mountains in County Down, Northern Ireland, 9km north of Kilkeel.  It is the third highest mountain in Northern Ireland at 747 m .  The summit is broad and flat with rocky tors at the north and south ends, with the "Back Castles", impressive towers of granite, in between.  To the south-west is Wee Binnian (from Irish: "Broinn Bhinneáin" , meaning "breast of Binneán" ) (460m).  It lies to the east of the Silent Valley Reservoir and the west of the Annalong Valley.  The Mourne Wall also crosses over Slieve Binnian.

Newfoundland Mountains: The Newfoundland Mountains are a 20 mi long mountain range located in southern Box Elder County, Utah, United States.  The range is the only 'island' mountain range encircled by the Great Salt Lake Desert salt flat.  Other ranges protrude into the desert salt flat, the Silver Island and Dugway Ranges being the premiere examples.  Other individual mountains also arise as 'island' peaks, or mountains in the salt flat desert itself, most notably Granite Mountain in the south desert, and Wildcat Mountain to its north.  Granite Mountain lies at the north of the Dugway Range.

Ben Crom: Ben Crom (from Irish: "Binn Chrom" , meaning "curved/stooped peak" ) is a 526 m mountain in the Mourne Mountains in County Down, Northern Ireland.  It is situated beside Ben Crom Reservoir, which is upstream from Silent Valley Reservoir.  The mountain is composed of granite.  An exposed area on the south west of the mountain shows where the Eocene aplitic granite meets the laccolith top of the older Mesozoic granite ring dike.  The summit of the mountain features granite crags which are crossed by basic and feldspar porphyry dikes.  The mountain is used for sheep grazing and hill walking.

Mourne Mountains: The Mourne Mountains ( ; Irish: "na Beanna Boirche" ), also called the Mournes or Mountains of Mourne, are a granite mountain range in County Down in the south-east of Northern Ireland.  It includes the highest mountains in Northern Ireland and the province of Ulster.  The highest of these is Slieve Donard at 850 m .  The Mournes is an Area of Outstanding Natural Beauty and has been proposed as the first national park in Northern Ireland.  The area is partly owned by the National Trust and sees a large number of visitors every year.  The name "Mourne" (historically spelt "Morne") is derived from the name of a Gaelic clann or sept called the "Múghdhorna".

Silent Valley Reservoir: The Silent Valley Reservoir is a reservoir located in the Mourne Mountains near Kilkeel, County Down in Northern Ireland.  It supplies most of the water for County Down, surrounding counties and most of Belfast.  It is owned and maintained by Northern Ireland Water Limited (formerly DRD Water Service).  The reservoir was built between 1923 and 1933 by a workforce of over one thousand men, nine of whom died.

George Matthew McNaughton: Sir George Matthew McNaughton CB (31 January 1893 – 31 August 1966) was a British civil engineer who specialised in hydraulic engineering.  McNaughton was born in Dundee and received a degree in engineering from the University of St Andrews.  He interrupted his studies to become an officer in the British Army during the First World War before he was forced to retire due to ill health.  After the war he completed his degree and joined an engineering firm where his work included the Silent Valley Reservoir in Northern Ireland.  In 1929 he entered government service at the Ministry of Health and eventually became the ministry's Chief Engineer.  His work was recognised by an appointment as a Companion of the Order of the Bath and a knighthood.  He retired in 1960 and served as President of the Institution of Civil Engineers for 1961-2.

Ben Crom Reservoir: Ben Crom Reservoir is a reservoir located in the Mourne Mountains near Kilkeel, County Down, Northern Ireland.  Along with Silent Valley Reservoir, which is situated further down the Kilkeel River valley, it supplies water for County Down, surrounding counties and most of Belfast.  It was constructed between 1953 and 1957, as the final part of the Mourne scheme to provide water to Belfast which started with the passing of the Belfast Water Act in 1893.

Supporting paragraphs: Silent Valley Reservoir Mourne Mountains
Answer: Múghdhorna