which trails are mtb's allowed on?

hey I'm new to vancouver so I have a noob question…

how do I know what trails mtb's are allowed on here? or are we just allowed anywhere?

i.e. if I see a park with a dirt trail (in the city or on the mountains or otherwise) how do I know if I'm allowed to ride on them?

is there a good listing of all allowed mtb trails around here? (or even just trails?)

cheers.

any trail that doesn't have a no bikes sign on it. Most are OK. Just respect hikers and walkers, slow down for them and stop for horses.