The Secret of Old Glory Mine (1976)

An old prospector, Charlie, living alone with his burro in Arizona tries to keep a rich silver vein a secret. He takes out only enough to pay his expenses. When another miner arrives, Charlie tries to dissuade him from finding the vein, but when he saves Charlie’s life, the two decide to share the secret.

Unfortunately the movie The Secret of Old Glory Mine is not yet available on HBO Max.