A long awaited test involved going up & down the mountain in 16mm sandals.

  The uphill segment was all done on trails.

Only the last part of this section entailed using 4 paws.  The rest of this section was gnarly but doable in the uphill direction.

Sadly, the sandals didn't have enough traction to attempt these 2 sections in the downhill direction.  The downhill direction was much gnarlier.  The laces weren't the problem, but the smooth soles weren't up to it.  There are no lugged 1mm soles.  Perhaps lugs can be glued on, but they're going to be heavy.  The great challenge continues to be steep sand covered clay.

Steeper sections with exposed rock were doable.  Rock hits in the downhill direction were painful.  The downhills had to be slower than in shoes.