Task: Question Generation
Input (English): Passage: Successful mining took time and capital, particularly once most of the timber around the Klondike had been cut down. A realistic mining operation required $1,500 ($1.2 million) for wood to be burned to melt the ground, along with around $1,000 ($800,000) to construct a dam, $1,500 ($1.2 million) for ditches and up to $600 ($480,000) for sluice boxes, a total of $4,600. The attraction of the Klondike to a prospector, however, was that when gold was found, it was often highly concentrated. Some of the creeks in the Klondike were fifteen times richer in gold than those in California Gold Rush, and richer still than those in Witwatersrand Gold Rush. In just two years, for example, $230,000 ($184 million) worth of gold was brought up from claim 29 on the Eldorado Creek.
Output (English): Which gold rushes were some of the Klondike creeks richer than?