Co-op Challeneges?

Looking on the challenges, could someone explain how do to a day trip, i click to start the challenge and it says go to start location, but no markers (as i can see on my map), so where do i go :cheers:
 
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United States
New Jersey
durWINNING
Noob Saibot 007
In the description it should tell you a start location for example the fountain in Carson or the dam