Eruption of central El Salvador's Ilopango Volcano early in the first millennium A.D. caused death, cultural devastation, and exodus of southern Mesoamericans. It also left a time-stratigraphic marker in western El Salvador and adjacent Guatemala—the Ilopango Tierra Blanca Joven, or TBJ tephra. Mineral suites and major element abundances identify a silicic volcanic ash in cores from Lago de Yojoa, Honduras, as Ilopango TBJ. This extends its reported range more than 150 km to the northeast. Analyses of glass from the TBJ tephra from the Chalchuapa archaeological site, El Salvador, and from Lago de Yojoa, Honduras, establish the first major element reference fingerprint for the TBJ tephra. The Lago de Yojoa cores also hold two previously undated trachyandesitic tephra layers originating from the nearby Lake Yojoa Volcanic Field. One fell shortly before 11,000 14C yr B.P. and the other about 8600 14C yr B.P.

Cenotes (natural wells or sinkholes) comprise the most common landscape features in the northern Maya Lowlands of the Yucatán Peninsula, México. Detailed study of dated soil‐sedimentary sequences, recovered from a cenote at the archaeological site T’isil and nearby wetlands, allows a partial reconstruction of environmental variability at the site for the last 2000 years. Biogenic calcite sedimentation and Calcisol development occur during three intervals of increased inundation in cenote and wetland environments, ca. A.D. 300, A.D. 1000, and A.D. 1300. Periods of increased inundation in the cenote and wetlands correlate with wetter climatic intervals, and periods of Maya occupation at sites in the Yalahau region. Evidence for Maya modification of the cenote environment may relate to regional wetland agricultural practices.

For historic property types such as archaeological sites and historic buildings, data recovery is often the main part of mitigation plans offered by federal agencies with undertakings that will destroy part or all of a cultural resource. In theory, by extracting important information before destruction, we recover some part of a historic resource's cultural value. In some situations, however, data recovery is impossible or otherwise undesirable, and “creative” or off-site mitigation measures are necessary to mitigate adverse effects. In such circumstances, the Washington State Department of Archaeology and Historic Preservation has accepted funding from federal agencies to create, implement, and enhance an online digital information system for cultural resources. This article describes the Washington Information System for Architectural and Archaeological Records Data (WISAARD) and provides an example of a federal agency funding WISAARD development as creative mitigation for the transfer of archaeological sites out of federal ownership. We discuss the benefits of such systems and address how their development meets preservation goals established by the Advisory Council on Historic Preservation.

In the acknowledgments section of this article (Wollwage et al. 2020) Shelby Manney's last name is misspelled. The correct last name is Manney.

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