The diversity of the Halkomelem dialects is noted to be the result of complex social and economic forces and linguistic change, as many Island people crossed the Georgia Strait to camp along the Fraser River (in both the Downriver and Upriver areas) for the summer runs of salmon. Arranged marriages between children in different language areas was also common, helping to establish a regional social network in the Strait of Georgia–Puget Sound Basin. Use and revitalization efforts The Halkomelem language is near extinction. In 2000, it was estimated that the number of fluent Halkomelem speakers was fewer than twenty-five. Most are middle-aged or older, and few are monolingual, as there was a flood of English-speaking settlers in the region in the mid-19th century. Language programs at the Stó:lō Nation, Seabird Island First Nation, and Cowichan First Nation have been developed to save the language. A program aimed at adults at Musqueam is a collaboration between the band and the University of British Columbia First Nations and endangered languages program. In September 2009, the University of California Press published American linguist Brent Galloway's Dictionary of Upriver Halkomelem. A Halkomelem iPhone app was released in 2011. This was followed by an Android version was released in 2016. The app was developed by the FirstVoices website. There are 1754 words archived and 690 phrases archived on the FirstVoices website. As of 2014, 263 fluent speakers had been reported. In 2014, the number of Head Start Programs was 21, and this included a language-nest immersion preschool. Phonology Note: All examples are drawn from the Downriver dialect of Halkomelem spoken by the Musqueam band. Relevant differences in the phonology of the Island and Upriver dialects are noted at the foot of the phoneme charts. Vowels Halkomelem has five vowel phonemes. Long and short vowels (but not schwa) contrast. Vowel length is written in the native orthography as . Upriver Halkomelem dialects also have a mid back vowel . All five vowel phonemes vary considerably phonetically. The phoneme /i/ has three distinct allophones. It is realized as following unrounded uvulars. It is realized as with a central off-glide preceding both unrounded and rounded uvulars. Elsewhere, it is realized as low or high . The /e/ is realized as a low to mid-front vowel, usually between or high . The /a/ is low and central to back, often close to . The /u/ is high, back, and