[2] On August 1, 1938, a section from Post to Garden City was designated, creating a gap.

[5] On August 27, 1940, the section of SH 207 from Big Spring to Garden City was cancelled.

On February 4, 1941, the section of SH 207 from Gail to 8 miles north of Big Spring was cancelled.

On February 28, 1945, the section of SH 207 from Ralls to Post was cancelled and transferred to FM 122.

On September 1, 1965, the route was extended north and south along its current route, replacing FM 122 south to Post, the portion of FM 284 north to Claude, a portion of the rerouted SH 15 to Sperman, and SH 282 to the Oklahoma state line.