Presidio Flour Trail?

Guys, please I need your help figuring this out

My friend and I were hanging out at the Yoda fountain last thursday 1/23 in the presidio when we saw a woman jogging with a tote bag, grabbing something from her bag and dropping it on the ground every so often. After a closer look she was dropping handfuls of baking flour?? Leaving a trail - small lumps of flour every so often.

We decided to follow the trail she was leaving behind which took us through the lucasfilm gardens, around the palace of fine arts, onto marina blvd, through crissy field, back over the freeway into the presidio ultimately leading back to the presidio where we started?? We got lost several times as some parts of the trail she was leaving behind had gaps and weird directions.

The trail was also following arrows on the ground; it seemed someone had previously drawn. In addition to this where symbols (such as a circle crossed out). Not sure the significance. We also saw the letters DGK written on the path right before returning to the yoda statue.

The weirdest thing is we seemed to be the only people following the path. We thought it could part of some running club but there was nobody else following the trail, we even asked multiple people on the path who thought we were crazy at the mention of following a flour trail.

Anyway, if you know anything about this please comment cuz im dying to know. Thanks!