The great majority of material in this dictionary was collected by Robert L. Oswalt starting in 1957 and lasting several decades. His tireless collaborator in this work was Essie Parrish, along with Herman James and several other speakers of the language. The latest manuscript of Oswalt's dictionary dates from 2005, and is located in the California Language Archive at the University of California, Berkeley. Bob Oswalt passed away in 2007.
In 2011, Eugene Buckley at the University of Pennsylvania began preparing the text manuscript for import into a Fieldworks Language Explorer (FLEx) database. This initial work was supported by a grant from the University Research Foundation and a School of Arts and Sciences Research Opportunity Grant, and largely implemented by Penn student John Gluckman.
From 2012-2015, Buckley continued to develop the dictionary database, supported by a grant from National Endowment for the Humanities under the Documenting Endangered Languages program. This included both improvement in the database entries and the connections among them (aided by Penn student Kobey Shwayder) and multiple trips to California for collaboration with Anita Silva (with participation by Gluckman) to gather more information and examples for the dictionary entries.
Further support was provided by the Penn Undergraduate Research Mentoring Program (PURM); this made possible the assistance of Catherine Liu and Logan Castrucci during the summer of 2016.
In 2017 and 2018, Buckley traveled to California to discuss the language with speakers Otis Parrish, Inez Adam, and Freda Davis.
Over the past several years, additional assistance on the project has also been provided by Penn students Jacob Kaufman, Jialin Wang, and Michael Ehart.