Pretty good reason to use serious safety chains when towing.

[skyhawk1]

Not required but still a good idea...

Oklahoma Trailer Hitch and Signal Laws

Every trailer, semitrailer (unless drawn by a truck-tractor), or manufactured home shall be equipped with chains or cables to prevent parting from the towing vehicle in the event that the coupling device breaks or becomes disengaged; or chains, cables, or a safety device that provides strength, security of attachment, and directional stability equal to or greater than that provided by safety chains that prevent the parting from the towing vehicle.

 

[MacFromOK]

Oklahoma Trailer Hitch and Signal Laws

Every trailer, semitrailer (unless drawn by a truck-tractor), or manufactured home shall be equipped with chains or cables to prevent parting from the towing vehicle in the event that the coupling device breaks or becomes disengaged; or chains, cables, or a safety device that provides strength, security of attachment, and directional stability equal to or greater than that provided by safety chains that prevent the parting from the towing vehicle.

When did that become law?

I probably haven't pulled a trailer in a couple decades...

 

[skyhawk1]

When did that become law?

I probably haven't pulled a trailer in a couple decades...

Been a law as long as I can remember and that is a ways back

 

[MacFromOK]

Been a law as long as I can remember and that is a ways back

Here's the only legislation I've found with rules about chains. It's dated 1999, but I don't know if that's original or a carry-over from earlier legislation.

"STATE OF OKLAHOMA
1st Session of the 47th Legislature (1999)
SENATE BILL NO. 6 By: Taylor"

Req. No. 24 Page 3

F. Every trailer, semitrailer or manufactured home shall be
equipped with a coupling device which shall be so designed and
constructed that the trailer, semitrailer or manufactured home will
follow substantially in the path of the vehicle drawing it without
whipping or swerving from side to side. In addition, every such
trailer, semitrailer or manufactured home, except a semitrailer
drawn by a truck-tractor type designed to draw or support the front
end of a semitrailer, shall be coupled with:

1. Stay chains or cables to the vehicle by which it is being
drawn, which chains or cable shall be of sufficient size and
strength to prevent parting from the drawing vehicle, should the
regular coupling device break or become otherwise disengaged; or

2. Chains or cables or a safety device which provides strength,
security of attachment and directional stability equal to or greater
than that provided by safety chains and which prevent parting from
the drawing vehicle should the regular coupling device break or
otherwise become disengaged. This device shall be designed,
constructed, and installed so that if the tow-bar fails or becomes
disconnected the tow-bar will not drop to the ground.

http://www.oklegislature.gov/cf_pdf/1999-00 INT/sb/sb6 int.pdf