Solution

"Minute steps climb" 60 steps (4 sets of 15), found at Battery Wagner, a gun emplacement built in Marin in 1900. While you must descend to the battery, you then climb steps to continue past the battery.

"beyond fingers rise" Five concrete pillars rise from the ground, roughly organized like 5 fingers, just below/beyond Battery Wager.

"onward on pins" There are pine trees here, and pine needles litter the floor. The trail to the fingers is through pine trees. If you clock the 60 steps, stone fingers and pins, and have pieced together the below clues about your vantage, you would hopefully be quite curious to continue exploring. There's a very little used path that skirts down and around to the base of the rocks that sit between Battery Wagner and the coast. It looks steep from afar, and is somewhat, but we did the scramble in sandals with the treasure and it quickly levels out at the base of the rocks.

"deem heavenly island towers" Sight the towers of the Golden Gate Bridge, protruding through the heavenly clouds. This Reddit comment/photo nailed it.

"over derelict ward" In 1901 Captain Ward made the 4am decision against better judgment to pull anchor and pilot the SS City of Rio de Janeiro into the golden gate's thick fog. His steamship was carrying tin, hemp, and sugar and 200 people. He ran the ship onto submerged rocks, it quickly sank, and Capt Ward went down with the ship. This was SF's deadliest shipwreck and was long rumored to have gone down with treasure. From our treasure you're looking across to the entire city, and at the GGB towers, which stand high above the wreck. Many hunters presumed this clue referenced any number of abandoned buildings, and it could, but we couldn't resist pointing to Willie Ward's famous shipwreck.

"stern wood haven north and powell, off back-ward" This is the only clue that you can stand in front of and know for certain this must be something. And it greatly narrows the scope of your search. All five names are on headstones in the Presidio cemetery, clustered in one small plot, nearest the water's edge, facing into the cemetery. Backward is to mean that off behind them is where you should be searching. If standing at the treasure they are off in the distance, their backs facing you. Find them and you'd know the treasure must be on this small corner of the city, or beyond it. The treasure is quite far off indeed, though these are technically within sight of the treasure and vice versa. This hunter found the headstones.

"under stone this mint rests buried in keep" The treasure is literally under stone, inside a cave, as all treasure should aspire to be. And further still, is buried just under the rocky edge of the cave. If you considered the above clues, and found the steps, pines, and fingers, and continued to find this little-known cave, there is now little doubt and hopefully much appreciation and wonder.

"please do take a seat" There is a ancient timber bench that someone hauled to this this special spot long ago—an amazing and near impossible to randomly discover perch that gazes across the bay and city. That there is a bench here is an unmistakable sign and surely must mean this is the spot. The pause is also a genuine ask. A nod to the arduous journey and to the harder, treasure-laden uphill one to follow.

"spare a moment... only we know this plane, this sanctum, this peep" There's a rare few who have shared this hollow and as for this exact gleeful moment of finding it so right for treasure—only us the treasure buriers and you the finders. These couple lines are a genuine love letter to the city and to you who hunt for the treasure. We shared such an experience locating this place and finding it so ripe for our riches and we can't help but appreciate your parallel journey. This "plane" is this elevation, "sanctum/peep" should harken to the cave, plus its altar-like bench.

"let's celebrate.... sole hunt for this haunt" Truly we mean to celebrate the city, the hillside scramble, the journey shared by only us (though also on foot... sole being a pun), and the sight you have from this vantage. "Haunt" speaks to the cave. And in general, if you're thinking like the treasure buriers, who have spoken about their love of classic treasure lore, caves and other iconography should be high on your list of possible spots. And while we expanded the radius beyond the city, our celebration of it means the hunt should probably be viewing it in some way. This Reddit comment was a particularly impressive read of all these sentiments.This read was as well.

"truly framed in full" The view from within the cave frames the city and bay view, and put another way, if you've made it here, you also now fully understand what all the clues have meant. 

"cast stage-left at your feet" Caves have an amphitheater quality, so stage-left is clear directionality. If you're seated on the bench in the cave, to the left-most edge at your feet there's a bit of soft ground, just under the rock, that can be dug. One foot down and there's the treasure. 

This an actual photo of us burying the chest in the cave. Yes, it looks like it must be an illustration. But it's not—it's just that fantastic. That much pure treasure. This hunt we couldn't resist such an adventurous spot. When—if—there is another hunt, it will certainly be more accessible. 

And if you think, "There's no way I could find this from a computer. Hundreds of us would have to literally wander the Presidio and the headlands for days, trading notes, collaborating, and exploring every nook and cranny, and even that might take a month…”

Yes.