Phormidium Mats

Phormidium Mats - 645Z, 28-45 @ 45mm, f/11, 1/80s, ISO 100.

These orange colored tendrils are Phormidium bacteria on the edges of the Grand Prismatic Spring in Yellowstone.  Almost every hot spring in Yellowstone has bacteria with different colors including orange, green, brown, red and yellow.