The oldest living tree species is known to be the Bristlecone pine (Pinus longaeva). These trees are found primarily in California's White Mountains and can live for thousands of years. One particular tree, named Methuselah, is estimated to be over 4,800 years old, making it one of the oldest non-clonal living organisms on Earth. The harsh climate and rocky soil conditions of their native environment contribute to their slow growth and remarkable longevity. Research into these ancient trees continues to provide insights into climate change, longevity, and the resilience of life in extreme conditions.