From my experience, most do not. You should call ahead first or ask when you get there. I wouldn't just walk in and just start drawing from a holster.....you might make someone pretty mad if they don't allow it. Some ranges see it as a safety hazzard. Someone inexperienced might shoot their foot off.
Yes we do allow drawing from the holster. With that said the shooter must remain in his/her stall and if the RO determines at anytime that the shooter is unsafe or unable to control the firearm while drawing, then the RO will assist or stop the shooter from continuing. Thank you Greg