This is the first time I've seen whatever these are. There were only 5 or so, so I didn't take one for a spore sample. Stouter than L. delicioso and larger and stouter than Hygrocybe conica (Witch's Hat). The ecology matches the books: late summer/early fall, subalpine ecosystem. These were in ponderosa. Morphologically, they don't have the convex cap, but perhaps that would come with age. Any opinions?
With those quite prominently curving out caps they don't look to me like anything Lactarius, but I don't know what they could be and am not an expert. Hopefully Frog will soon come to the rescue. In the meantime I am curious what makes you think they are Lactarius sp.?
Just desperate in guessing at Lactarius. L. olympianus was the closest photo I could find. When I saw it in the field, my first thought was huge Witch's Hat, but then quickly, no. Then Tricholoma but I don't see anything like that. Another possibility ... Hygrophorus coccineus or H. speciosus , but those are not listed as being in the Rockies.
Take a look at Hygrocybe conica in E-Flora BC; it shows specimens in the Rockies and cap diameters up to 12 cm.
