Engelmann Spruce: Picea engelmannii (Synonyms: Picea engelmannii var. engelmannii, Picea engelmannii ssp. engelmannii, Picea engelmannii var. glabra, Picea glauca ssp. engelmannii, Picea glauca var. engelmannii) - Needles 4-angled, about as wide as thick and measuring about 2.5 cm long. Whitish stomatal lines on all surfaces. Female cones about 4-5 cm long. Common above 3000' on the mountain.
White Spruce, Western White Spruce, Porsild Spruce, Black Hills Spruce: Picea glauca (Synonyms: Abies canaensis, Picea alba, Pinus alba)
Sitka Spruce: Picea sitchensis (Synonyms: Abies falcata, Picea falcata, Picea menziesii, Pinus menziesii) - Needles flatter, about twice as wide as thick and measuring 1-1.5 cm long. Whitish stomatal lines on the upper leaf. Female cones about 6-10 cm long. At this point, only seen on moist ground on the lower south slopes of Mt. Adams.