Almost everyone with the least smidge of north-of-the-Rio-Grande Mormon exposure knows that, in a Mormon context, “Happy Valley” means… well, not everyone agrees.  It can be BYU, Provo, Utah County, Salt Lake Valley, the Wasatch Front, Utah, the whole Mormon Culture Region. It can be mocking, ironic, humorous, or straightforward and can be because people are “really, really friendly”; “the Mormon influence and sheltered lifestyle”; the “bland, cheery optimism in the face of reality”; “peace, joy, and tranquility”; the many Mormons; the “prevailing LDS positive thinking.” And so on. 
The most famous “Happy Valley” is a utopia in Samuel Johnson’s novella Rasselas, or the Prince of Abyssinia (1759) and many of the 19th-century uses of “Happy Valley” refer explicitly to it.  In (anti-)Mormonism, Nauvoo was the first Happy Valley: “Mormonism is a religion invented to raise the price of land…. It is expected [that in-migrants will] purchase town lots and water privileges in this “Happy Valley.”  In an oft-cited 1850 speech, Thomas Kane gave an un-ironic, if over-enthusiastic, description of Salt Lake Valley: “The pages of Malte Brun provide me with a less truthful parallel to it than those which describe the happy Valley of Rasselas, or the Continent of Balnibarbi.”  In subsequent decades, Mormon “Happy Valleys” appeared frequently in non-Mormon literature conveying non-ironic beauty, ironic social merit, ironic physical merit, delusion, or vague derision. [6, 7, 8, 9, 10] (If you’re not reading the footnotes, the quote from Mrs. Kane is worth checking out. Also: poxes on you.)
Parley Pratt provides the earliest Mormon usage of “Happy Valley,” but not in reference to Mormons.  An 1858 citation responds to the phrase in an anti-Mormon piece but puts it in scare quotes.  In 1867, however, AN MacFarlane embraced the idea in a nine-stanza poem in the Millennial Star—appropriate for a Mormon on the periphery and for a reference to Johnson. 
…See the efforts they are making
To subdue the desert land,
See the temple they are rearing,
To fulfill the Lord’s command.
Oft our thoughts in silence wander,
To that Valley in the west
Oft we speak to one another,
Of that happy day of rest.
When we with other Saints will gather
To that place of safe retreat,
Meet our friends, and in our gladness
Shout aloud, with joy complete.
Mormons wrote of Happy Valley in generic and Mormon senses in the latter nineteenth century but not often and with no apparent irony. 
From there, the happy trails grow spotty. In 1906-1907 the Juvenile Instructor ran Rasselas as a serial; in 1923 the Improvement Era published a short story wherein “Happy Valley” was only accessible to the pure in heart; in 1969, Newsweek discussed BYU race-relations under the heading, “Trouble in Happy Valley.”  Sometime during the mid-twentieth century, “Happy Valley” transformed from common-noun literary device to proper-noun patois.
Now for speculation: Marc Haddock surmised that “Happy Valley” attached to Provo because the assimilating railroad went through Ogden instead; this seems reasonable to me.  I conjecture, however, that there were a few more factors.
- Growing peripheral Mormon populations meant more people looked to the center (or, more precisely, geographic dispersal and accelerated assimilation on the geographic periphery created the center qua center);
- Diasporans tend to idealize the “homeland,” and the limited number of temples meant there was a steady stream of pilgrims to that “homeland,” especially because…
- Emphatic endogamy and the great meat-market in the tops of the mountains at BYU meant that, by the late twentieth century, a large percentage of North American adult Mormons had youthful experiences at BYU-and folks tend to idealize their youth.  Therefore…
- The institutional and strategic developments relating to BYU in the latter twentieth century played an important role. Also…
- Valuable and useful though the Honor Code be, nothing says “surreal literary fantasy-land” like stringent rules for non-criminal, non-military adults. And, finally…
- I bet Walt Disney’s 1947 Mickey and the Beanstalk, which interpreted “Jack and the Beanstalk” in the setting of an idyllic “Happy Valley,” put a generic “happy valley” idea back in low-brow circulation-especially among Mormons, who (anecdotally, at least) watch lots of Disney. 
Almost the end: I wish you, as your situation warrants… happy hunting, nostalgia, anticipation, and/or mockery in/about Happy Valley. Happiness all around (remembering that too much cynicism desiccates souls.) And thus wished, I, along with ex-Brighamite, ex-Godbeite, Josephite Edward Tullidge, bid “farewell to the Saints and sinners of the happy valley.” 
 Of course, “Happy Valley” is a fairly common geographic appellation. <en.wikipedia.org/wiki/Happy_Valley>, accessed 2009 Jul 07. Richard Poll cites a paper, “The Happy Valley Concept,” by Leonard J. Arrington, but I failed to locate the document. Richard D. Poll, History & Faith: Reflections of a Mormon Historian (Salt Lake City: Signature books, 1989), Chapter 4, note 1, <www.signaturebookslibrary.org/history/chapter4.htm>, accessed 2009 Jul 03. The Utah State University and University of Utah collections also identify such materials. LJ Arrington Papers, Box 72: General Research Files, Folder 5: Happy Valley Concept (12 items). <library.usu.edu/specol/manuscript/Arrington/LJAHA1/inventorypt9.html>, accessed 2009 Jul 03; Polk papers, Box 76: Critiques (1931-1992), Folders 14-16: Leonard J. Arrington, “The Happy Valley Syndrome” (1969). <db3-sql.staff.library.utah.edu/lucene/Manuscripts/null/Ms0674.xml/ContainerList>, accessed 2009 Jul 03.
 “Sure, everyone’s friendly here [in Provo]. Really, really friendly. Even the folks in Salt Lake City call Provo “Happy Valley.”” David Lamb, “Provo Isn’t Friendly by Accident, Gosh Darn It,” Los Angeles Times, 2002 Feb 24, <http://articles.latimes.com/2002/feb/24/news/mn-29635>, accessed 2009 Jul 03; “”I would sooner go to hell than to Provo,” [Abraham O.] Smoot [allegedly told Brigham Young]. Young sent Smoot to Provo anyway, and folks in Salt Lake City have been making fun of Happy Valley ever since.” Jesse Hyde, “A tale of two cities: Oft-maligned Provo and Orem are the dynamic duo,” Deseret News, 2003 May 08, <findarticles.com/p/articles/mi_qn4188/is_20030508/ai_n11397592/>, accessed 2009 Jul 03; “…Provo is still largely Mormon. …The area is sometimes referred to as Happy Valley because of the Mormon influence and sheltered lifestyle.” Jessie L. Embry, Mormon Wards as Community, p33 <3AXJPX4HpEkC>; “”Happy Valley” …is what many people mockingly call the Provo area.” <www.ericdsnider.com/snide/wyoming2k/>; “The Wasatch Front …has earned the derogatory nickname “Happy Valley,” primarily for its bland, cheery optimism in the face of reality.” <6-bleen-7.livejournal.com/43282.html>; “Happy Valley is used widely to describe a place where one can find peace, joy and tranquility.” <alumni.byu.edu/features/happy-valley-anywhere.cfm>; “[Utah County’s] “Happy Valley” nickname presumably reflects the BYU influence that has made it the most Mormon (90%) county of the core.” Richard Lee Nostrand and Lawrence Ernest Estaville, Homelands: A Geography of Culture and Place Across America, 2001, p203 <4ZiXBABDxUcC>; “The whole Salt Lake Valley is sometimes called “Happy Valley,” in ironic reference to prevailing LDS positive thinking.” Richard Mercer Dorson, Handbook of American Folklore, 1986, p203 <eoqdSXEekTcC>; ““It’s like Happy Valley here,” she said, describing the Salt Lake Valley. “It’s a scary place sometimes. People don’t talk about their problems. Everything is always rosy. That’s how we got ourselves into this mess–we’re good at ignoring things.”” Julie Cart, “Study Finds Utah Leads Nation in Antidepressant Use,” Los Angeles Times, 2002 Feb 20, <www.ils.unc.edu/~unsworth/mormon/miscellaneous.html>, accessed 2009 Jul 03.
 <www.gutenberg.org/ebooks/652>, accessed 2009 Jul 07. Allusions to Rasselas were frequent; Google Books [2009 Jul 07] returns 91 hits for <“happy valley”> between Jan 01 and Dec 31, 1847. As an example: “…if [Robert Owen, the socialist]’s plan for regenerating mankind was so excellent,” why did he not “endeavour to set it in motion in some newly-discovered country, such as the West of America or Australia…?” The Brighton Herald references a French innovator, Cabet, who “represented the inhabitants [of his experimental settlement] as being as happy as and far more contented than those described by Dr. Johnson as dwelling in the Happy Valley….” The Reasoner had a brief, critical vignette on Mormonism on the same page. George Jacob Holyoake, ed., The Reasoner 1849 Jan 17, p47 <03UAAAAAYAAJ>.
 William Harrison Ainsworth, ed., “Whitehall and the Battery: A Farcical Scene of Action,” By Uncle Sam, Ainsworth’s magazine: a miscellany of romance, general literature, & art, Vol 3 (1843):163. Throughout this post, “the earliest…” always carries an implied “that I’ve located as of the posting date.”
 “…Deseret is emphatically a new country…. Descend from the mountains, where you have the scenery and climate of Switzerland, to seek the sky of your choice among the many climates of Italy, and you may find welling out of the same hills the freezing springs of Mexico and the hot springs of Iceland, both together coursing their way to the Salt Sea of Palestine, in the plain below.” Thomas L. Kane, “The Mormons: A Discourse Delivered before the Historical Society of Pennsylvania, March 26, 1850,” The Latter-Day Saints’ Millennial Star 13 no 12 (1851 Jun 15) <WWMoAAAAYAAJ> p178. Conrad Malte-Brun [or Malthe Conrad Bruun] was a geographer of repute; Balnibarbi is a place in Tom Swift’s Gulliver’s Travels. The Kane piece was reproduced frequently: e.g., Henry Mayhew, Charles Mackay, The Mormons: Or Latter-day Saints: With Memoirs of the Life and Death of Joseph Smith, the American “Mahomet” (London: Office of the National Illustrated Library, 1851) p225 <ZYYsAAAAYAAJ> (with multiple later editions); Stephen Jenner, Truth’s Conflicts and Truth’s Triumphs; Or, The Seven-headed Serpent Slain: A Series of Essays, with an Allegorical Introduction on Some Chief Errors of the Day (New York: Longmans, Brown, Green and Longman, 1854), <jMhCAAAAIAAJ>; Millennial Star 38 no 15 (1876 Apr 15); Daniel Tyler, John Taylor, Thomas Leiper Kane, A Concise History of the Mormon Battalion in the Mexican War, 1846-1847 (1881) p103.
 “In less than twenty years the valley of the Salt Lake seemed in a fair way to resemble the Happy Valley of Rasselas….” (The Living age …? (1877) p780). “The valley of Bear River…reminded me continually of the Happy Valley, where the royal race of Abyssinia exhausted their lives…” (Maria Ward, Female life among the Mormons, by the wife of a Mormon elder, 1855 p157 Ch32); “In the midst of this happy valley, a picture of oriental beauty…” (Albert Deane Richardson, Beyond the Mississippi: from the great river to the great ocean: life and …? ,1869, p344).
 [From Mrs. Kane this time:] “…The [family] had been pioneers, I learned, in diverse dismal settlements. They were among the founders of that ‘Happy Valley,’ in Nevada, where the dogs scratched savagely in the sand for places to cool their burning feet, and hens threw themselves on their backs and waved their claws in the air with the same end in view.” Elizabeth Wood Kane, Twelve Mormon homes visited in succession on a journey through Utah to Arizona, 1874 p133.
 “Verily, the most wretched women on earth were in this happy valley by Jordan’s stream….” M. A. C. “A Glance at the Latter-day Saints,” The Irish Monthly 18 (Dublin: 1890 Jun) p317 <MYYAAAAAYAAJ>.
 “Proselytes were courted and won by descriptions of a new Happy Valley …and superstitious weakness will help to lock the Mormon chains around her” Justin McCarthy, “Brigham Young,” The Galaxy 9 no 2 (New York: 1870 Feb) p180 <XTIZAAAAYAAJ>.
 “Towards this ‘happy valley’ no less than 2,500 persons…undertook to journey in the single year of 1849” (no author listed, “Mormonism,” The Monthly Christian Spectator 1 (London: 1851 Nov) p666 <TQEAAAAQAAJ>). “…seen an angel, the mountain, and the happy valley in a prophetic dream” (no author listed, “Salt Lake City and the Mormons,” Ballou’s monthly magazine? 36 (Boston: 1872) p13). “The following specimen scrap …describes the happy valley of the Salt Lake…” (William Scott, Francis Garden, James Bowling Mozley, The Christian Remembrancer (1857) p275); “…to follow their great leader to the happy valley among the mountains of Utah” (John H. Keatley, History of Pottawattamie County, Iowa: Containing a history from the … (O.L. Baskin & Co,1883) p22); “…his shrine, the object of his long wanderings, hardships, and perils, the Happy Valley of the Great Salt Lake….” (Richard Francis Burton, The City of the saints: and across the Rocky mountains to California (1862) p191); “…in the happy valley of the Mormons” (James Bonwick, The Mormons and the Silver Mines (1872) p295).
The connection to Rasselas continued in the forefront throughout the nineteenth century. An 1895 usage made a direct comparison: “When Brigham led his followers into the Happy Valley, they were, indeed, separated from the whole world….” (James Andrew Corcoran, Patrick John Ryan, Edmond Francis Prendergast, eds. The American Catholic Quarterly Review, 1895, p488). That said, perspectives were changing on both Mormons and Dr. Johnson. A 1900 piece removed some of the cynicism: “The …discovery of gold in California and the…railroad brought the persecuting Gentiles into the happy valley…” (Edwin Erle Sparks, The expansion of the American people, social and territorial (1900) p416).
 Pratt’s autobiography, published posthumously in the 1870s, uses “happy valley” in connection with an 1839 incident; he died in 1857. The Autobiography of Parley P. Pratt, Ch. 33, ¶2. The only hit for “happy valley” in the Overland Trails Diaries collection at BYU is a description of Yosemite in California. Colfax, Schuyler, 1823-1885 p24, Overland Trails Diaries, BYU, Harold B Lee Library, Digital Collections, <contentdm.lib.byu.edu/cdm4/document.php?CISOROOT=/Diaries&CISOPTR=7642&REC=1>, accessed 2009 Jul 03.
 ELT Harrison, “Elder Harrison’s Reply,” The Latter-day Saints Millenial Star 20, no. 35 (1858 Aug 28), p548. HFQoAAAAYAAJ. Robert Richards, an anti-Mormon writer put “happy valley” in a Mormon mouth in 1854, but I have been unable to verify or corroborate the usage. “In this happy valley, as we deemed it, we should acquire another Canaan after our perils in the wilderness.” Californian Crusoe [Robert Richards], The Californian Crusoe; or, The lost treasure found (1854) p117 <D7MBAAAAQAAJ>.
 A. N. MacFarlane, “The Happy Valley,” The Latter-Day Saints’ Millennial Star 29 no 10 (1867 Mar 09):160.
 Blanche Beechwood, “Ambition,” Women’s Exponent 5 no 2 (1876 Jun 15):14; Aunt Em, “Pleasant Springtime,” Women’s Exponent 8 no 23 (1880 May 01):179; “If there are more temptations than there were once ‘in our happy valley,’ then the strength to resist these evil influences should be doubled with the grace and integrity obtained by the supreme heights attained.” Emmeline B. Wells, “The Year of Grace 1891,” Women’s Exponent 19 no 4 (1891 Jan 01):108; “…here and there all the way backward over the rugged and rough hills of memory we find nestled far down in the happy valley of remembrance sunny spots in our lives where fancy loves to linger….” Amethyst, “Happy Moments,” The Latter-Day Saints’ Millennial Star 41 no 5 (1881 Oct 31):69-70, quoting the Salt Lake Contributor.
 Dorothy Carolyn Retsloff, “Happy Valley,” The Improvement Era 27 (1923 Nov):47; “Trouble in Happy Valley,” Newsweek 74 (1969 Dec 01): 102-103.
 Marc Haddock, “Provo’s progressed over its 160 years,” Deseret News, 2009 Jun 07. <www.deseretnews.com/article/705309188/Provos-progressed-over-160-years.html>, accessed 2009 Jul 03. Also: Mormon Times, 2009 Jun 09.
 And you don’t need more than two drops of cynicism in your body to be just a wee bit sarcastic about a place your parents go on and on about.
 Edward William Tullidge, History of Salt Lake City, 1886, p548. <en.wikipedia.org/wiki/Edward_Tullidge>, accessed 2009 Jul 07.