Rifleman:

That Close and LRRP definition was one of many BAD results of Viet Nam where one of the more ridiculous SOPs became that no US troops could operate outside US Artillery support fans. Both Brigades I was in ignored the rule totally at the times I was there; most obeyed it. We picked up a lot of really bad habits in that war...

Prior to that foolishness, the rule of thumb was that close was indeed inside organic and DS fire support range but that was the province of the Companies. The Battalion Reconnaissance Platoons (recall they were mounted where Scouts are not) had no close or distance restrictions, it was simply a METT based decision and I've operated 60-70 km out for three to five days at a time on many occasions. We pulled two mounted missions in Viet Nam when I was the acting PL and there were no distance or support limits. The rest of the time, we used Helicopter insertions and those were frequently 50-100 km away from everything.

The Separate Brigades in VN had LRP Platoons and Cav Troops. What they did depended on th Bde Cdr. That was all general practice in training prior to VN. After VN, we got stupid.

Van:
...how many U.S. COs would use scouts outside of logisitical support range for any length of time;
Probably 'not many'. But having the capability for those special occasions, and maintaining the standards would be worth the training and logistical investments.
True on both counts. The Commanders are constrained by yet another Viet Nam myth and our newly acquired risk aversion. That needs to go. The current TOEs are a 1990s production designed to save spaces and money; it is not a wartime TOE -- and that tradition of peacetime design has hurt the US Army on many occasions.

I'd note that the Scouts being dismounted are far more a result of the cost of a HMMWV being ten times the cost of the M151 it replaced than any logical doctrinal or tactical reason...
...the principle is whether you choose to 'dumb down' your soldiers or provide them the training and tools to exceed your expectations.
EXACTLY! We continually do this. Criminal.

Fuchs
...thinks he meant this to be about armoured recce
He may think that but that's not exactly what he said: LINK. No intent to hijack but recce is a broad topic. In US usage, Scouts generally do dismounted stuff, Cavalry does mounted stuff and Reconnaissance or recce is the act that both perform. All that said not to pick on you, but after three 'mad' icons above, I wanted to leave smiling.