I found at a local park pathway with (NEMA?) shoebox fixtures with an unusual sticker/tag.

Tag is a white background with a '7' inside of it. Is it even a NEMA?

Would be 70W HPS, though it is more common for the tag to be yellow

Most of those tags are plastic. Some plastics degrade in sunlight (even indirect) and change color - It could be then anything - yellow (HPS), red (MH). It could be blue (mercury) if a 70W mercury lamp would exist but it does not

They aren't always colored.  Sometimes they are white, grey, or clear and just indicate wattage.

Aren't the white tags for MH's? So 70W MH...

I have to go there at night to be sure, as Toronto is mostly lit by HPS (except for downtown core, which uses MH).

White is sometimes used for HPS, though more likely it has just faded. So I'd say it's a 70 watt HPS.

I'd agree with Niall and icefoglights, I noticed that some tags weren't colour coded and since he said it was outside of downtown Toronto I'd say it's a 70w HPS...