It weighs in at nearly six pounds, fills more than 1,000 pages, and represents the work of many hands and hearts.

The Klallam people’s first dictionary for what was always an unwritten language was built syllable-by-syllable, from tapes and spoken words transcribed into a phonetic alphabet.

The work was a race against time: About 100 people spoke Klallam as their first language when he first began learning Klallam in 1978, said Timothy Montler, a University of North Texas linguistics professor, and author of the dictionary. By the time the dictionary was published by the University of Washington Press last September, only two were left...