Teslin Tlingit Council (TTC) Chief Richard Sidney calls it a "monumental step" for his First Nation.
On Friday, the First Nation signed an intergovernmental agreement with Yukon government, essentially committing both to work together on some shared priorities.
"We have an agreement!" Sidney declared to applause as he and Premier Sandy Silver signed the document at a gathering in Teslin.
"It's taken us a while to create this relationship, to establish this understanding," Sidney said.
The agreement states that it's meant to facilitate "economic, social, cultural and development decisions," while protecting the TTC's aboriginal and treaty rights.
It also lists topics of priority to work together on, including forestry, education, subdivision development, infrastructure and tourism. The list "may be amended from time to time," the agreement says.
In a statement, Silver said the document "paves the way for closer collaboration."
Sidney said it's about building on the TTC's final land claim agreement, signed in 1993.
"This agreement embodies our commitment to collaborate on issues that are fundamental and are so important to our respective citizens."