Tahltan is a poorly documented Northern Athabaskan language historically spoken by the Tahltan people (also "Nahanni")

Tahltan

Tahltan refers to a Northern Athabaskan people who live in northern British Columbia around Telegraph Creek, Dease Lake, and Iskut.-Social Organization:...

 who live in northern British Columbia

British Columbia

British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

 around Telegraph Creek

Telegraph Creek, British Columbia

Telegraph Creek is a small community located off Highway 37 in Northern British Columbia at the confluence of the Stikine River and Telegraph Creek. The only permanent settlement on the Stikine River, it is home to approximately 350 members of the Tahltan First Nation, as well as another 50...

, Dease Lake

Dease Lake, British Columbia

Dease Lake is a small community located in the Cassiar Country of the Northern Interior of British Columbia, Canada. Located only a few hours south of the Yukon border, it is located on Highway 37 at the south end of the lake of the same name. Dease Lake is the last major centre before the Alaska...

, and Iskut

Iskut, British Columbia

Iskut is a small, mostly aboriginal community in the Stikine Country of northwestern British Columbia. It is located on Highway 37, at the north end of Eddontenajon Lake just south of Dease Lake and the crossing of the Stikine River...

. Some linguists consider Tahltan to be a language with 3 divergent but mutually intelligible dialects (Mithun 1999). The numbers below are according to Poser (2003):

• Tahltan   (approximately 35 speakers)
• Kaska
  Kaska language
  Kaska is a Northern Athabaskan language spoken by the Kaska people in the southeastern Yukon territory and northern British Columbia in Canada.-References:***...
  
     (approximately 400 speakers)
• Tagish
  Tagish language
  Tagish is an endangered Northern Athabaskan language spoken by the Tagish people in the Yukon Territory in Canada. It is almost extinct as there are only two fluent speakers left.Tagish is closely related to Kaska and Tahltan...
  
     (approximately 2 speakers)

Other linguists consider these to be separate languages.

Consonants

The 45 consonant

Consonant

In articulatory phonetics, a consonant is a speech sound that is articulated with complete or partial closure of the vocal tract. Examples are , pronounced with the lips; , pronounced with the front of the tongue; , pronounced with the back of the tongue; , pronounced in the throat; and ,...

s of Tahltan:

		Bilabial Bilabial consonant In phonetics, a bilabial consonant is a consonant articulated with both lips. The bilabial consonants identified by the International Phonetic Alphabet are:...	Inter- dental Interdental consonant Interdental consonants are produced by placing the blade of the tongue against the upper incisors...	Dental		Post- alveolar Postalveolar consonant Postalveolar consonants are consonants articulated with the tongue near or touching the back of the alveolar ridge, further back in the mouth than the alveolar consonants, which are at the ridge itself, but not as far back as the hard palate...	Palatal Palatal consonant Palatal consonants are consonants articulated with the body of the tongue raised against the hard palate...	Velar Velar consonant Velars are consonants articulated with the back part of the tongue against the soft palate, the back part of the roof of the mouth, known also as the velum)....		Uvular Uvular consonant Uvulars are consonants articulated with the back of the tongue against or near the uvula, that is, further back in the mouth than velar consonants. Uvulars may be plosives, fricatives, nasal stops, trills, or approximants, though the IPA does not provide a separate symbol for the approximant, and...	Glottal Glottal consonant Glottal consonants, also called laryngeal consonants, are consonants articulated with the glottis. Many phoneticians consider them, or at least the so-called fricative, to be transitional states of the glottis without a point of articulation as other consonants have; in fact, some do not consider...
				central	lateral			plain	labial
Nasal Nasal consonant A nasal consonant is a type of consonant produced with a lowered velum in the mouth, allowing air to escape freely through the nose. Examples of nasal consonants in English are and , in words such as nose and mouth.- Definition :...	plain	m		n
	glottalized			nʼ
Plosive	unaspirated	p		t				k	kʷ	q
	aspirated							kʰ	kʷʰ	qʰ
	ejective							kʼ	kʼʷ	qʼ	ʔ
Affricate Affricate consonant Affricates are consonants that begin as stops but release as a fricative rather than directly into the following vowel.- Samples :...	unaspirated		tθ	ts	tɬ	tʃ
	aspirated		tθʰ	tsʰ	tɬʰ	tʃʰ
	ejective		tθʼ	tsʼ	tɬʼ	tʃʼ
Fricative Fricative consonant Fricatives are consonants produced by forcing air through a narrow channel made by placing two articulators close together. These may be the lower lip against the upper teeth, in the case of ; the back of the tongue against the soft palate, in the case of German , the final consonant of Bach; or...	voiceless		θ	s	ɬ	ʃ	ç	x	xʷ	χ	h
	voiced		ð	z	ɮ	ʒ		ɣ	ɣʷ	ʁ
Approximant Approximant consonant Approximants are speech sounds that involve the articulators approaching each other but not narrowly enough or with enough articulatory precision to create turbulent airflow. Therefore, approximants fall between fricatives, which do produce a turbulent airstream, and vowels, which produce no...							j		w

Phonological processes

• Vowel flattening.
• Consonant harmony
  Consonant harmony
  Consonant harmony is a type of "long-distance" phonological assimilation akin to the similar assimilatory process involving vowels, i.e. vowel harmony.-Examples:...
  
  
• Vowel nasalization
• Vowel laxing