A portion of this tour will include a visit to a native population of Hackberry trees. This population grows on the fringes of its natural range in a small spring-fed canyon near Sidney called Lehman Springs. This is an area surrounded for miles by treeless shortgrass prairie. The cool waters of a spring-fed creek have supported a grove of Hackberry trees there that has been carbon-dated back 18,000 years based on fossilized seeds.