How does the Sierra Madre de Chiapas extend from Mexico into Guatemala?

The Sierra Madre de Chiapas is a crystalline range of block mountains that extends southeast from the Isthmus of Tehuantepec in Mexico along the Pacific coast into western Guatemala. Upon crossing the border into Guatemala, the range is referred to simply as the Sierra Madre.1

The transition between these two regions is marked by the Tacaná volcanic cone, which sits directly on the Mexico-Guatemala frontier and serves as a prominent feature at the southern extreme of the Chiapas Highlands. While the range continues into Guatemala, the country's broader topography is further defined by a distinct string of volcanoes that extends eastward from the Tacaná Volcano toward El Salvador.123