The size of the place isn’t certain but what we do know it’s divided into Sectors, the known ones are A-G.
Black Mesa itself was built during the 1950’s, possibly earlier, over decommissioned ICBM silos. Not everything in the facility is perfectly up-to-date, there are many dilapidated areas in the facility. However, there are modern electric monorail trams in place, though even some rail trains are used for transporting materials in the more industrial areas.
Relying on no one outside for power, the facility makes use of nuclear energy and hydroelectric power along with standard electricity. Supplies are a different matter, the Freight Yard is the import sight for raw materials.
Tens upon thousands are employed at Black Mesa, including the Security Force and Science Team. Employees and their families live in the facility, in dormitories. Exploring the facility, you will come upon arcades, libraries, cafeterias, pools, lounges, you name it, Black Mesa feels just like home. There’s even a newspaper available, The Mesa Times.
No place is perfect. Things do go wrong at Black Mesa. Gossip among the employees states that the military has a “dangerous and very efficient clean-up crew” to take care of any uncontained problems in the facility. Little do they know these rumors are true, and will find out in the coming weeks…