Martial law.

[Jack]

Having been involved 'loosely' with some of these ideas I can only make an educated guess at the how's... But a nationwide lockdown would be counter productive to man power, as has been the theme of BP's point.
It's likely that large rural areas near cities and towns may have a small detatchment to enforce the entire area but would be more of a visual presence than active. Large urban areas with the heaviest populations would be policed with the best resources and the majority of forces.
Utilising CCTV, ground forces etc and in an extreme situation drones or other aerial recce...
In Afghanistan a curfew was in effect that mainly US and Briish forces governed.
There is little to no CCTV and was to dangerous in some places to deploy ground units, aerial recce was used almost exclusively in finding curfew breakers. One piece of footage I was shown that was shared by the yanks showed three locals near a built up industrial type area, after seconds of detection a chopper was deployed a minute later it was on top of them, one was shredded immediately by the on board cannons, one tried jumping a fence got the same treatment, the third hid under a vehicle which done him no good as the 50mm rounds left the truck showing up as a white blur on the infrared... If the gov wanted to control and enforce a curfew it could and would without warning or hesitation, you can't reason with soldiers that have orders and even less so with ammunition travelling at thousands of miles per hour in your general direction...
So I would say that Scythe and BP are right in what their saying. Being so far out of the way you will not be of interest unless the term 'homegrown terrorism' gets used and then I'd worry even in the remotest of areas (as they will all be monitored - if only periodically).
The benefits are the same that scythe has mentioned with networks of people etc (in towers) and also have the advantage to get the latest news on lifted curfews, aid etc. of course there's an opposit and negative potential that they'd be the first to have the doors kicked in and face a death squad... But these scenarios, though worth talking about, come from an invasion stand point where we would be under occupation. At the very most in the traditional SHTF scenarios (in these cases it would be post shtf but whilst the powers that be tried to hold on) we'd expect the lightest of all restrictions and methods of enforcement discussed until a time that the country recovered or was abandoned...