Per the title the Golden Spike refers to the last spike used to connect the east and west portions of the Transcontinental Railroad on May 10, 1869 at Promontory Summit, Utah.
Frank Wilcox plays "Mr Henderson" from 'Tri-State Oil Company' to inform the layabout Joseph P. Carson, that the golden spike hit one of their oil lines. Wilcox also plays John Brewster from the OK Oil Company in Tulsa, who bought the Clampett's oil in "Beverly Hillbillies"
The $6.00 hotel bill (for a two day stay WITH meals) would be the equivalent of about $48.50 in the year 2022.