Fluvial response to Late Pleistocene–Holocene climate change in the Colorado River drainage, central Texas, USA: COMMENT

Gutiérrez and Stockli (2023) present detrital zircon U-Pb geochronological data and channel morphological characteristics from terraces along the lower Colorado River of the Texas Gulf Coastal Plain to assess fluvial response to Late Pleistocene and Holocene climate change.This paper has many interesting aspects, but we have concerns about the following statement, which plays a key role in their interpretations: "The headwaters region included eastward-flowing streams that originated at the Rocky Mountains and flowed across the Llano Estacado [aka the Southern High Plains, or SHP] and Simanola Valley, New Mexico."Below we discuss characteristics of the SHP that preclude Rocky-Mountain-sourced rivers flowing across the SHP as recently as the latest Pleistocene.