Azusa Valley, before the 1850s, was a wilderness of ancient live oak trees; thick stretches of cactus, chaparral, and sagebrush; and large boulders from thousands of years of erosion. Pioneers staked claims and began to clear the land. Though many gave up and moved back East, the permanent settlers persevered, and Glendora emerged as a town around 1887. Glendora incorporated in 1911, and an immensely profitable citrus industry kept it thriving. Today it is a quaint community, proud of its citrus-trade heritage.