Chief Poking Fire's main claims to fame are probably owning and running an Indian museum, and founding and running a tourist village. He also apparently presented Canadian Prime Minister Mackenzie King with an Indian head-dress in 1948. The story that he was a Ukrainian Soviet WWII pilot who survived being shot down and escaped to Canada to become an Indian chief is pure fabrication.
According to this ancestry page, his full name was Jean Baptiste Sawatis Atsienharonkwas Macomber, and he was born in 1896. More details on his ancestry can be found in John Masiewicz's Gervase Macomber And His 26 Children in Kahnawake. His wife, Louise (or Gathering Words), in addition to assisting her husband in his varied enterprises, was also (as Louise McComber) a nurse's aide and Director of the Kateri hospital in Caughnawaga (this link downloads a pdf). According to both the ancestry page and Masiewicz's book, the couple were married in 1917.
The most straightforward account of Chief Poking Fire is probably this:
The Poking Fire "set-up" was a tourist attraction developed by John
McComber, also known as Chief Poking Fire, in the village of Kahnawake
in the 1930s. Originally known as "Chief Poking Fire Totum [sic]
Pole Indian Village," McComber's enterprise provided visitors with a
highly staged representation of Indians as exotic others.

Source: Historic Images of Kahnawake
The 1954 article The High-Flying Braves Of Caughnawaga has the following not incompatible account. The real Caughnawaga
laugh good-naturedly at John Macomber assuming the title “Chief”
Poking Fire. There hasn’t been an authentic chief of the village since
the tribal system of government was abolished by Ottawa in 1890. But,
as they point out, there’s nothing to stop anyone from calling himself
“Chief,” and Poking Fire has his own little tourist village where he
parades around in Hollywood Indian costume to the delight of the
tourists and the enrichment of fellow villagers who operate stalls
within his compound.
The blue-eyed “Chief” is admired too for the tenacious way he built up
his village from a shaky start in 1929 when, with twelve dollars to
his name, he refused to ask for government help. Instead he built a
wigwam and advertised with a crude sign the Indiancraft he and his
wife made—they didn’t have the money then to buy the factory product.
Today, thirty-two families take part in Poking Fire’s tourist village,
and when the weather is good they do a thriving business.
John Macomber, not to be confused with the Harvard Business School lecturer / businessman, died in 1979, leaving his 'enterprise' to his descendants. Both T.E.D. and jamesfq have noted that some of the attire at least is not of the Kahnawake region (and Poking Fire was clearly in the tourist business with little regard for historical or cultural accuracy), but there seems to be no real evidence that he was some kind of Caucasian impostor.
One story found on the internet is that John Macomber (or John McNober) may or may not have been Ukrainian Soviet air force pilot Ivan Dodoka, supposedly shot down and killed during World War II before escaping to Canada and becoming Chief Poking Fire. He was then discovered, the story goes, by a visiting Soviet delegation who heard the Indian chief speaking Ukrainian. However, pre-war photos clearly disprove this story. For those interested, a film based on Ivan Dodoka's alleged experiences (Firecrosser) was released in 2012.

Source: British Museum (dated 1930s)