Glen Haven is a very small community with a volunteer fire department. The fire station is located in the downtown area of Glen Haven (which isn't very big). You can see the downtown area on Google Maps Street-view here: http://g.co/maps/ncgm4
When there is a fire, the Estes Park fire department will most likely respond as well if it is serious enough.
As far as fire hydrants, I don't believe there are any in the glen haven area.
Let me know if you have more questions about Glen Haven! Its a great little community in the mountains!