I have no info on gate but the sign as of Aug 23 2017 states:

JOCK MAINLINE
Radio Controlled Access Only!
Notice: Under the Authority of the Section 54.01 of the Public Lands Act this road is closed beyond this point for the purpose of :
Wildlife Management
Fisheries Management
Water Management 
Vegetation Management 
Security
Safety
Unauthorized on-highway motor vehicles are prohibited. Operators of unauthorized vehicles beyond this point may be found guilty of an offence.
Warning: Gate may be locked without warning
In case of emergency call Sundre Forest Products Emergency
Phone: 1.888.478.6373
For general inquiries contact Sundre Forest Products at 1.877.638.4482

Commercial users contact the Land Use Coordinator at 1.877.638.4482

DLO#971962