The portion of United States highway 75 where it enters the state on the Kansas-Nebraska border on the north then south to the junction with K-9, then south from the junction of K-9 with K-62 to the junction of K-62 with K-16 then east to the junction with United States highway 75 then south on United States highway 75 to the southern city limits of Holton, then from the junction of United States highway 75 and interstate highway 70 in Shawnee county then south on United States highway 75 to the southern boundary of Osage county, then from the northern city limits of the city of Yates Center south on United States highway 75 to the northern interchange with United States highway 400, then south from the southern interchange with United States highway 400 to the Kansas-Oklahoma border, is hereby designated the purple heart/combat wounded veterans highway. The secretary of transportation shall place markers along the highway right-of-way at proper intervals to indicate that the highway is the purple heart/combat wounded veterans highway. The secretary of transportation may accept and administer gifts and donations to aid in obtaining suitable highway signs bearing the proper approved inscription.