Lava Beds National Monument Stronghold, which is 450,000 years old. Petroglyph Point was created about 275,000 years ago when cinders erupted through the shallow water of Tule Lake; violent explosions of ash and steam formed layers upon layers of tuff. The caldera is thought to have formed by subsidence, during which basalt and andesite were erupted up on the slopes. Lava flows dated to about 30,000–40,000 years ago formed most of the lava tube caves in the monument. As the hot basaltic lava flowed downhill, the top cooled and crusted over, insulating the rest of the lava and forming lava tubes. Lavacicles on the
Lava bear Alfred Bayne. As late as 1981, scientist were being asked to identify small bear tracks in the Fort Rock area to determine if they were made by lava bears. Today, it is accepted that lava bears are actually common American black bears. It is also generally acknowledged that all of the animals that were killed or captured between 1917 and 1934 were either black bear cubs or small adults stunted from malnutrition. In 1924, Bend Senior High School selected the lava bear as the school’s sports mascot. The mascot was chosen shortly after a living bear was exhibited in Bend.