Mount Shasta is a non-fictional potentially active volcano located in the northern California as part of the larger Cascade Range of volcanoes. It is the primary location of several chapters of Las Tortugas Ninja; the Tortugas Ninja fly there on the Turtle Blimp after Splinter tells them that Kurko was trapped there eons ago. They arrive there during El Espíritu de la Tierra and spend the entirety of El Espíritu de la Tierra: La Continuacion and El Encuentro de Dos Fuerzas there.
Bufalo Rojo and Kutuk are sentinels of the Mount Shasta area, guarding it against intruders. After Bufalo Rojo wipes the floor with Turtles, he is stopped by Kutuk, who takes the Turtles to see Yang. Yang's other half, Yin, is weakened by Kurko, and Yang implores them to defeat Kurko and restore balance, transforming them into El Gran Terrapín.