Klondike event (4,4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
gold rush
(Other definitions for gold rush that I've seen before include "of Olympic sprint?" , "Stampede of prospectors" , "Large migration of people to a new field of precious metal" , "California 1849 mania" , "Prospectors' chase" .)