Identification of individuals within a species is vital for monitoring population dynamics and determining appropriate conservation efforts. Traditional methods for marking individual lizards include toe-clipping, branding, tattooing, and passive integrated transponder (PIT) tags. However, some of these methods can potentially cause stress, affect performance and survival, and raise concerns about the ethical treatment of animals. We conducted a long-term study on the urban ecology of Texas horned lizards living in two small towns in south Texas, USA. Our study was in the unique position of possessing a dataset of individuals that were PIT tagged, genotyped, and photographed which allowed us to validate genotyping and natural markings for individual identification. Our genotyping had low error rates and high power to identify individuals, additionally, individual spot patterns were unique and stable across years. We used HotSpotter software to match photographs and had a success rate of 94%. This could be increased to almost 100% by looking at the top 10 picture matches by eye to validate the matching. Using pictures of ventral spots is an easy way to identify individuals, avoids potential rare instances of infection or mortality, and is inexpensive relative to PIT tags and genotyping.