Over millions of years organisms lived, died, and evolved. Some of these plants and animals are preserved as fossils in the sedimentary rock of today. A fossil is a record of the preserved remains or traces of prehistoric plants and animals. Fossilization is a process where an organism is covered with layers of sediment. The sediment is compressed under the pressure of more and more layers until it is finally compressed into rock.
Minerals eventually replace the organic parts of the plant or animal until it is formed into stone.
Fossils will remain in stone until they are uncovered by erosion or movements of the earth's crust. In British Columbia, ancient sediments and the fossils they contain have been pushed to the surface during mountain formation.