Overall length

I have travelled coast to coast and border to border with a 40ft and a 45ft DP pulling a 32ft trailer and have never had a problem. That's 72 and 77ft over all. I don't know about legal but I have never been stopped. And by the way several years ago here in NC the RV length was raised to 90ft if involved in motor sports. These laws are "iffy" and first most police don't understand them and the judges know less so you travel at your own risk.

in January my friend with a 42 ft tiffin and a flatbed trailer with 2 Polaris rzr atvs was stopped between Abilene and El Paso TX he was
67 1/2 ft long, it cost him $270, they did allow him to continue but suggested getting a permit as another trooper could give him another ticket. some depends on how good the trooper is at judging length, this one was with the DOT unit so he was better than the average bear

This the current Montana law according to my DOT book and the Internet. I have Class 8 trucks.
Montana

Size Limitations: Height, 14'; Width, 8'6" (special wide body regulations); Trailer length, not specified (total maximum combined length of 75'); Motorhome length, 55'; Combined length, 75'. Triple towing is allowed but not to exceed maximum combined length of 70'.

All vehicles over 21' (including bumpers) and 8' wide (including mirrors) are not permitted through Logan Pass at summit of Going-to-the-Sun Road in Glacier National Park. Shuttle service is available between St. Mary and West Glacier. Restriction from Avalanche Campground on south side to Sun Point area on the north side

Required Equipment: Safety chain, breakaway switch, flares or reflective signs, brakes required on trailers with unladen weight of 3,000 pounds.

Riding is permitted in fifth wheel and pickup campers only.

Overnight parking is "as posted" in state rest areas. Current April 20 2017.

Ivylog wrote:
Since the question was about MH plus trailer, not commercial triple towing I posted the best one I've found as it references MH length and exceptions for RVs. I also warned it may not be current. Pretty sure a MH at 75' in MT will not be legal.

A motorhome towing two trailers would have to obey the 75 foot limit.
A motorhome towing nothing would be a single unit, and be limited to 55 feet long.
A motorhome towing a vehicle or trailer would be limited to 65 feet.
Again, read MCA 61-10-104. The word(s) "commercial" or "for hire" do not appear in the law.

Since the question was about MH plus trailer, not commercial triple towing I posted the best one I've found as it references MH length and exceptions for RVs. I also warned it may not be current. Pretty sure a MH at 75' in MT will not be legal.

LVJ58 wrote:
Here's a site you may want to visit regarding towing laws including length's.

http://onlinetowingguide.com/towing_laws.html

Best of luck & Safe Travels.....:)

That one is a little better, but the 75 foot limit in Montana is for truck/trailer/trailer combinations only.

For reference, see MCA 61-10-104. In general, single unit; 55 feet max. Two units (truck/trailer) 65 feet max. Three units (truck/trailer/trailer) 75 feet max, and the rear unit must have breakaway braking.

It pays to have a good working familiarity with the laws in every state you enter. Of course, that is nearly impossible.

Ivylog wrote:
The above link is out of date... this ONE is newer but not necessarily current. It does have exceptions in some states for RVs that the one above does not have.

It is not correct for Montana. The maximum length for a three unit combination (truck/trailer/trailer) is 75 feet.
If they can't get something that simple correct, what does it say about the rest of their site?

Recently many of the states with short lengths have come into the 21th Century... many of the posts above are using old max lengths. Almost every example Tatest gave are out of date. KY is now 65' and yes Delaware and NJ are 60 and 62' BUT they both have an exception for RVs of 65'. Al, IL, IN all have exceptions for RVs... 65'

While 65' is not universal, it's the norm for the majority of states for RVs.

These laws are on the books but rarely enforced. I am right at 65 feet or a bit more and have towed in every state in the lower 48 with no issues. The police don't even give me a second look. As stated above, it could happen, but I have read few if any instances of RVs being stopped to be measured.

Ed C wrote:
We have towed a 20' truck with our 40'8" MH with 5' of tow bar between them all over the country (75,000 miles) without issue. Now we are 2 1/2' longer and will not worry about it.

Just so long as you don't cry about other people feeling entitled and having no respect for the law