K-25 is a Kansas State Highway that runs from Oklahoma State Highway 136 (SH-136) at the Oklahoma State Line to Nebraska Highway 25 (N-25) at the Nebraska border, running through Leoti, Colby, and Atwood plus many more towns along the way.
K-25 enters Kansas from Oklahoma, acting as a continuation of SH-136. K-25 continues relatively due north through flat land until it meets US Route 56 and K-51. K-25 turns northeast on the two routes, which K-25 is concurrent with until Hugoton, when K-25 and K-51 split off of US 51. North of town, K-25 splits off of K-51, and K-25 continues in the same fashion as it did, passing through Ulysses, where US 160 is intersected, Lakin, where K-25 junctions US 50 and US 400 at the same time, and Leoti, where K-96 is intersected. After leaving Leoti, K-25 continues due north for about 20 miles, until the route turns east for about 8 miles, until turning back north, immediately passing through Russell Springs. North of Russell Springs, US-40 is intersected, sharing an overlap for about ten miles. After turning onto US 40, the road starts to become hillier. K-25 separates just west of Baker. From there, it goes north to Colby, traveling through lightly rolling hills. Just south of Colby, I-70 is junctioned, with a good number of services near the interchange. K-25 then becomes a 4 lane divided highway until it enters Colby, where it changes back into a surface street. Within the Colby city limits, US 24 is intersected. K-25 continues out of Colby, alternating between flat and rolling land. In Atwood, US 36 is intersected. K-25 leaves Atwood traveling through rolling hills at first, but flattens out as it continues north. K-25 exits Kansas into Nebraska where N-25 continues toward Trenton, Nebraska.