Description: From Riehle (1985): "...only 1 [tephra] younger than the 3650 yr [Hayes tephra set H], have been recognized."
"Another comparatively minor eruption between 500 and 1000 yr ago is also assigned to Hayes volcano."
From Waythomas and Miller (2002): "A single bed of volcanic ash (fig. 6 [in original text]), geochemically similar to the other known Hayes ashes, was erupted about 500 years ago (Riehle, 1985). Although the aerial extent of this ash deposit is not well known, the ash bed probably records a minor eruption of the volcano about 500 years ago."
From Dixon and Smith (1990): "The unit is a pale brown (10YR 6/3 to pinkish white (7.5YR 8/2) volcanic ash. It is typically 3 to 5 cm thick, but commonly occurs up to 8 cm thick. Mineralogically it is indistinguishable from the Watana tephra (s)."
From Mulliken (2016): "High geochemical similarity and the generally homogenous glass composition among samples of the Devil tephra within the mSRV [middle Susitna River Valley, Alaska] suggest that it represents a single eruptive event. High similarity between the Devil tephra and proximal Hayes Volcano reference tephra suggest that the Devil tephra is a product of Hayes Volcano and perhaps even the Hayes tephra set H. Riehle (1985) reports on a Hayes Volcano sourced tephra layer dating younger than 1605-1990 cal yrs B.P. at sampling site 27, which coincides with the range of dates that bound the Devil tephra in the mSRV [middle Susitna River Valley, Alaska] (Figure 6.1 [in original text]). Riehle (1985), however, does not provide a physical or chemical description of this young tephra, making a correlation only tentative. Future tephra sampling near Hayes Volcano may clarify the origin and distribution of the Devil tephra as well as improve the current knowledge of the timing of hazards posed by Hayes Volcano."