When the Rocky Mountains rose skyward along the length of our continent, the trench between that newborn landscape and the next ranges to the west was generous. Over hundreds of thousands of years the great river valleys and the plains at the bottom of the trench became lush with vegetation and animal life. While the craggy peaks themselves remain bare of growth, packed with ice, sand and clay, the trench offers sturdy range grasses and forests of pine, fir, larch and cedar. At a point just north of the 49th parallel, creeks and rivers rush down the slopes to the Kootenay going south, the Columbia flowing north. This junction is known as the East Kootenays and Cranbrook is situated within it.
Latitude - 49 deg 30' N.
Longitude - 115 deg 45' W.
Elevation - 920 metres above sea level (3,020 feet)
Large deposits of unconsolidated sediments made up of glacial drift, silt, sand and gravel underlie the region.
The Rocky Mountains are largely composed of Palaeozoic carbonate rocks that have been thrust over younger Mesozoic clastic and coal bearing deposits. The Purcell Mountains, on the other hand, are composed of predominantly pre-Cambrian meta-sedimentary rocks with intrusions of granitic bodies of varying sizes and styles.
The soil is composed of some brown and grey wooded soils and some porous areas, which undoubtedly contain large reservoirs of underground water.
Because a large portion of the City is built upon an old lacustrine plain and two alluvial fans, the City is relatively flat; however, this flatter area is surrounded by gradually rising hills where residential areas have been built. The elevation of the built-up areas varies approximately 78 metres (255 feet), from 905 metres (2,970 feet) at the junction of Cranbrook Street and 20th Avenue North to 983 metres (3,225 feet) at Pinecrest.