There were only a limited number of post offices, covering a wide regional area, that received Mailgrams and put them in the mail. The one serving Oklahoma was, I believe, located in Wichita, Kansas, which meant with the vagaries of the Postal Service's mechanized mail routing that a Mailgram took two days from Wichita to Oklahoma City (160 miles). This was usually no faster than it would have been by ordinary mail.
In the days before the Postal Service went to a mechanized mail sorting and distributing system, Wichita to Oklahoma City, and v.v., was overnight. So was Kansas City to Oklahoma City and v.v., Fort Worth and Dallas to Oklahoma City and v.v., Wichita Falls to Oklahoma City and v.v.'
Now, mail between Lawton, Oklahoma, and Wichita Falls, Texas, about 40 miles apart and considered a single market area, takes two days. Unless you use the curious and unusual mailbox at the Lawton post office marked "Wichita Falls only," which presumably bypasses the mechanized system and goes directly from Lawton to Wichita Falls, rather than making a mechanized stopover in Oklahoma City and another one in the Dallas-Fort Worth area. (Yes, they have three mailboxes rather than the usual two -- "Local," "Out of Town." "Wichita Falls only."
Wes Leatherock snipped-for-privacy@aol.com snipped-for-privacy@yahoo.com