California offers a variety of rock types due to its complex geological history. The document describes the author's process of collecting and identifying different rock samples from locations in California such as Yosemite National Park. Through online research of geological maps and the scientific method of questioning, hypothesizing and testing, the author was able to determine they had collected examples of igneous rocks such as granite and andesite, metamorphic rocks such as gneiss and phyllite, and sedimentary rocks including conglomerate and siltstone.