Frontier plum

Had some Frontier plums this week from a local nursery. I had never heard of them previously. Turns out, they are delicious!

They have all the appearance of a Japanese-style plum. Purple exterior. Rich sweet juicy plummy red flesh inside.

I tried to do some research on this variety and found out very little.

Can any of you tell me more about this plum? Disease susceptibility? Vigor? Genetic heritage? Commercial availability? Scionwood source? Etc?

Thanks.

I don’t see anything… I wonder if they are a local thing?

If it’s what I think, I would try an old nursery in one of the inland valleys of CA (maybe Fowler?) or CRFG. I think it’s from a breeding program in CA. U.C. Davis has a picture among its list of cultivars of historic significance in California.