Death of an artist : [a mystery] / Kate Wilhelm.

Enhanced descriptions from Syndetics:

In Kate Wilhelm's latest crime novel, a small Oregon town is rocked by a wheels-within-wheels case of art, fraud, and murder.

Silver Bay, Oregon, a small coastal resort town with nearly a thousand residents, is home to three generations of women: Marnie, the long-widowed owner of a small gift shop; Van, her granddaughter, who is about to graduate medical school; and Stef, mercurial, difficult, and a brilliant artist who refuses to sell her work.

When Stef discovers that Dale Oliver--the latest husband/paramour in a very long line--is trying to sell her work behind her back, she puts a stop to it and threatens to do the same to him. Shortly thereafter, Stef dies in an accident in her studio, and Dale shows up with a signed contract granting him the right to sell her work.

Convinced that Stef was murdered in order to steal her artwork, Marie and Van--grandmother and granddaughter--decide to do whatever is necessary to see that Dale doesn't get away with any of it. This includes enlisting the help of the new stranger in town, Tony, a former New York City cop, who might be the only one who can prove it was murder and bring the killer to justice.