Fluid leaking on block behind alternator

Was filling air on my tires today when I noticed some fluid on the block behind the alternator. Felt it and it felt more watery than oily so I’m leaning coolant. The coolant resivour was also empty. The head gasket obviously is leaking but I don’t think that’s the cause for the fluid on the side of the block. Can post some better photos if needed and plan on cleaning the block and checking it, but was wondering if anyone has seen this before.

 

I have agree, looks like oil.

Does it leave drops on the ground? A trick I like to do, mark one front & one rear tire locations on the ground with a sharpie.

O
T

Kinda like that except straight. Then when you move it, you know exactly where to look under for a leak.

Since the coolant reservoir is empty, the radiator may be low. If the engine is hot right now, add some coolant to the reservoir. If cold, pop the radiator cap & see if it’s low, top off as needed.