Can anybody tell me the History of hancock/yale oil company?

not affiliated with Hancock Oil Company of California .. ...

Yale Oil Co. was out of South Dakota, with refineries in Wyoming and Montana. Central office in Billings.
Distributed Hancock oil and grease, sold Litening gas
Yale Oil started a new refinery in Billings in 1930
in 1944. Carter Oil, a national concern, purchased the Yale Refinery in Billings .. ...

John and Luke Hancock started the Pure Oil of Minneapolis in the early 1900's. They sold out to The Pure Oil Company of Ohio in 1920. Luke Hancock continued to work for Pure Oil, and John Hancock started the Hancock Oil Company in Minneapolis. John Hancock died in 1929, at which time the Minneapolis Hancock Oil stations were sold to Phillips. I should research this area a bit more to get definitive information, but in the late 1920's, Yale Oil was incorporated in either South Dakota as Randy mentioned (or Montana, i'm not sure which), which i'm guessing had something to do with 1) Luke Hancock eventually leaving Pure, and 2) John Hancock passing. I believe Luke Hancock had some ownership in Yale, so I think he left Pure to work for Yale around this time, You'll see cans for the Hancock Oil company and Yale Oil which look identical. I think it's because prior to the Phillips sale, Hancock Oil and Yale Oil essentially had the same owners, and were just using the same cans with different company names.

I have more information at home. If anyone wants more details, i'd be happy to provide them.

A couple of more pics: note the JH on the can, which is the same as the bucket on the top pic. JH for John Hancock, which would tell me that its from the late 1920's.

I've seen a few of these 1lb. grease cans but don't recall seeing the Montana version, all have been from Twin Cities (MInnesota)
the Montana version must be pretty rare or so the seller thinks so. .. ...

https://www.ebay.com/itm/1930s-OLD-...City-Billing-MONTANA-rare-1/392059598785

Thank you all for the help and info.