Need help on a formula please.

MTC

I am needing some help on a formula. I want to count the number of times the following occurs in two columns of data: 1) where a value is unique/distinct AND where that value exists in another column with a certain value. Example: Unique station name and and "city" . Have tried several combinations and am stumped. Appreciate any help and time.  

One example tried.

=COUNTIFS((DISTINCT(station2:station77),(District2:District77, "Dallas"))

Paul Newcome

Try this:

=COUNT(DISTINCT(COLLECT(station2:station77, District2:District77, "Dallas")))