Who are the characters in the story "All Gold Canyon" by Jack London? Who is the protagonist and who is the antagonist in the story?

There are only two characters in the story "All Gold Canyon" by Jack London, both of whom are anonymous miners.
The protagonist is the first of the miners we encounter. He is sometimes referred to as the "pocket-miner" but is not actually given a name. Although the story is written in the third person, this miner is a viewpoint character. The story follows his experience closely and the narrator has full access to his thoughts and perceptions. The narrative arc of the story follows his experiences, beginning with the discovery of the canyon, followed by a growing rise in his fortunes as he discovers the gold, his excitement as he traces its precise location, and then a decline in fortunes as he is shot by another miner, a climax which reports his struggle with the other miner, and a resolution in which he leaves the canyon with his gold.
The antagonist is the second miner or "stranger" who shoots the pocket miner in the back, struggles with him, and is eventually killed by him. The stranger has apparently followed the miner to the canyon, waited until the miner found the source of the gold, and then, after letting the first miner do all the work of prospecting, attempted to kill the first miner and steal the gold. After his death, the pocket miner comments about him:

"Never laid eyes on him before," the miner concluded his scrutiny. "Just a common an' ordinary thief, damn him! An' he shot me in the back! He shot me in the back!"

In the story, the miner refers to the vein of gold for which he is searching as "Mr. Pocket." Although the source of the gold is not human, it almost functions as a character in the eyes of the miner.
The miner's horse and a buck (male deer) that inhabits the canyon are also described in the story, but are not really characters.