BIG10/BTN Overflow Channels 1314 and 1315 Not available to me

I do not see BTN overflow channels 1314 or 1315 in my area. These are used to show BIG10/BTN sporting events that are area-specific and are not carried on the regular Big10 channel. For the last 2 weeks BTN has referred Xfinity customers to these channels for Washington Husky football viewers