Chan was hit and killed while walking her dog in Alameda two weeks ago.
RELATED: Alameda County Supervisor Wilma Chan dies after struck by car while walking dog
She was the first Asian American to be elected to the board, in 1994.
She also served in the state assembly, and later returned to her supervisor seat.
"There are things we could depend on Wilma to do, to raise, to push, to have the intellectual capacity to state, to have the courage and boldness to go forth," Alameda County Supervisor Nate Miley said.
RELATED: Intersection where Supervisor Chan was killed identified as a high-injury intersection by Alameda
"We could depend on that from Wilma. We don't have that anymore, and it's sad. It's sad. It saddens me," he said.
Chan's Chief of Staff Dave Brown was appointed to serve out the rest of her term.
He says he won't run for the seat next year.
VIDEO: Colleagues, friends remember Alameda Co. Supervisor Wilma Chan as selfless public servant