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Sierra El Viejo
Sierra El Viejo (Cerro Viejo, Sierra del Viejo) is a limestone mountain range near Caborca in northwestern Sonora, Mexico, 850 m high, with Precambrian rocks, bighorn sheep, and endemic agaves; distinct from a 3,500 m Nuevo León namesake.
Sierra Entertainment
Sierra Entertainment (Sierra On-Line, originally On-Line Systems) was an American game company founded 1979 by Ken and Roberta Williams, pioneer of graphical adventures (Mystery House, King's Quest), sold to CUC in 1996, closed 2008, revived as an Activision indie label in 2014.
Sierra Ferrell
Sierra Ferrell, West Virginia-born Nashville roots singer-songwriter, won four Grammys at the 2025 ceremony for Trail of Flowers and American Dreaming, and was Americana Music Association Artist of the Year in 2024 and 2025.
Sierra funding round
The Sierra funding round of May 2026 raised $950 million for AI customer-service startup Sierra Technologies, led by Tiger Global and GV at a $15 billion valuation.
Sierra Gorda Biosphere Reserve
Sierra Gorda Biosphere Reserve (Reserva de la Biosfera Sierra Gorda), a UNESCO MAB reserve in Querétaro, Mexico, decreed 1997; biogeographic convergence zone with 1,718 plant and 363 bird species, ecotourism economy, and mercury-mining threats.
Sierra International Network
Sierra International Network is a California startup founded by Emil Hakim in 2024, based in Irvine, that runs equity-crowdsourcing and gig-worker platforms and is seeking a NASDAQ listing.
Sierra La Laguna Biosphere Reserve
HP Sierra la Laguna (Reserva de la Biosfera Sierra La Laguna) is a 112,437-hectare biosphere reserve decreed in 1994 in Baja California Sur, Mexico, protecting the state's only pine-oak forest, its main aquifer recharge zone, and many endemic species.
Sierra Leone
Sierra Leone, West African coastal republic, capital Freetown, independent 1961, civil war 1991-2002, President Julius Maada Bio re-elected 2023, Freedom House Partly Free 61/100, HDI 0.458, ECOWAS member.
Sierra Leone (horse)
Sierra Leone, 2021 dark bay colt by Gun Runner out of Heavenly Love, $2.3 million yearling, won 2024 Breeders' Cup Classic and Whitney, 2024 champion 3-year-old male, trained by Chad Brown, retired to stud for 2026.
Sierra Leone Civil War
The Sierra Leone Civil War (1991-2002) pitted the government against the RUF rebels backed by Charles Taylor's Liberia, killed about 50,000 people, displaced over 2 million, and ended with the Lomé Accord, a Truth and Reconciliation Commission, and the Special Court that convicted Taylor.
Sierra Leone Colony and Protectorate
The Sierra Leone Colony and Protectorate was a British West African possession: a Crown colony at Freetown from 1808 and a hinterland protectorate from 1896 until independence in 1961.
Sierra Leone diamond mining reforms
Sierra Leone diamond mining reforms are the legal, institutional, and revenue-sharing changes made since the 1991–2002 civil war to curb smuggling and fund mining communities.
Sierra Leone national football team
Sierra Leone national football team, the Leone Stars, men's national team governed by the SLFA (founded 1960, FIFA/CAF). Never at a World Cup; three Africa Cup of Nations appearances: 1994, 1996, and 2021.
Sierra Leone People's Party
The Sierra Leone People's Party (SLPP) is one of Sierra Leone's two dominant political parties. Founded in 1951 by Sir Milton Margai, it led the country to independence in 1961.
Sierra Leone River Estuary
Sierra Leone River Estuary: 295,000-ha estuarine and mangrove wetland near Freetown, Ramsar site no. 1014 since 1999, third-largest natural harbor, key waterbird and manatee habitat, an MPA with weak legal protection.
Sierra Leone under Siaka Stevens
Sierra Leone under Siaka Stevens was the 1968 to 1985 period in which he ruled, first as Prime Minister, then as President of a one-party state.
Sierra Leonean leone
The Sierra Leonean leone is the currency of Sierra Leone, issued by the Bank of Sierra Leone and redenominated in 2022, when 1,000 old leones became one new leone.
Sierra Leonean refugee crisis
The Sierra Leonean refugee crisis was the mass displacement of Sierra Leone's population during the civil war of 1991 to 2002, which drove about 460,000 refugees into Guinea and Liberia.
Sierra Madre (Philippines)
The Sierra Madre is the longest mountain range in the Philippines, running 540 kilometers along Luzon's eastern coast across 10 provinces, holding about 40 percent of the country's forest cover.
Sierra Madre de Chiapas
Sierra Madre de Chiapas (Chiapas Sierra): 280-km Pacific-coast mountain range in southern Mexico averaging 2,000 m, part of the Maya block near the Cocos-Caribbean-North American triple junction, uplifted mainly in the Miocene, home to El Triunfo and La Sepultura biosphere reserves.
Sierra Madre del Sur (landform)
Sierra Madre del Sur, a mountain range in southern Mexico arcing from Michoacán to Oaxaca along the Pacific coast; about 1,100 km long, a Tertiary magmatic province, and a high-endemism biogeographic province and pine-oak ecoregion.
Sierra Madre del Sur (protected area)
Sierra Madre del Sur, FEOW freshwater ecoregion 170 (not a formal protected area), Neotropic coastal rivers of Guerrero and Oaxaca, Mexico, draining Pacific slopes of the Sierra Madre del Sur; major rivers Petatlán, Papagayo, Verde, Colotepec.
Sierra Madre Occidental
Sierra Madre Occidental, western Mexico's great silicic volcanic plateau and mountain range (also Sierra Tarahumara), runs over 2,000 km from the US border to the Trans-Mexican Volcanic Belt, formed by Farallon subduction and Gulf of California rifting.
Sierra Madre Oriental
Sierra Madre Oriental: major folded mountain range in eastern Mexico, one of Mexico's 14 biogeographic provinces, over 1,000 km long, a Jurassic-Cretaceous limestone fold-thrust belt deformed during the Laramide orogeny.
Sierra McClain
Sierra Aylina McClain, American actress and singer born 1994 in Georgia; McClain Sisters member; known as Nessa in Empire, Tanya Clifton in Mindhunter, and Grace Ryder in 9-1-1: Lone Star (2020–2023), leaving before season 5 in a contract dispute.
Sierra McCormick
Sierra McCormick (Sierra Nicole McCormick, born 1997) is an American actress known for Olive Doyle on Disney's A.N.T. Farm, Fay Crocker in The Vast of Night, and roles in Some Kind of Hate and American Horror Stories.
Sierra Minera de Cartagena-La Unión
The Sierra Minera de Cartagena-La Unión is a 25 km coastal mountain range in Murcia, southeast Spain, whose silver-lead ores were mined from Phoenician times until 1992.
Sierra Mist
Sierra Mist was a lemon-lime flavored soft drink produced by PepsiCo, introduced in the United States in 1999 to compete against Sprite and 7 Up, and discontinued in January 2023.
Sierra Morena de Sevilla UNESCO Global Geopark
Sierra Morena de Sevilla UNESCO Global Geopark, formerly Sierra Norte de Sevilla, is a 177,484-hectare natural park in northern Seville province, Spain, a UNESCO Global Geopark since 2015, home to the El Pintado 1 Ordovician–Silurian GSSP.
Sierra Nevada
Sierra Nevada: major mountain range of eastern California, about 640 km long, a granitic Mesozoic batholith with Mount Whitney (4,421 m); its snowpack supplies about one-third of California's water.