[LucyT]

Since Denver is at 5,280 feet, I was wondering how fleas could survive and spread bubonic plague at that altitude.

[Myrddin]

Since Denver is at 5,280 feet, I was wondering how fleas could survive and spread bubonic plague at that altitude.

Focus on temperature ranges, not altitude. Denver has ideal flea temperature ranges from May to September. Denver also has lots of precipitation in that time frame.

[MamaDearest]

Since Denver is at 5,280 feet, I was wondering how fleas could survive and spread bubonic plague at that altitude.

When we lived there in the 70's, there were prairie dogs in the fields near the foothills and most certainly prairie dogs continue to be one of the prime carriers of fleas and plague.

City of Boulder warning of prairie dogs infected with plague in August 2005