how is a trailer length measured?

Nobody is going to come out of the office & measure the trailer. When asked how long the trailer is the answer is always what is in the model number even though the true exterior length is a couple feet longer. We have yet to go into a supposedly 30' limit SP or NP that did not have a few sites big enough to accomodate us. We have often hung over beyond the pad length with a drop off too high to use the rear stabilisers. Big deal. So the trailer wobbles a little. Don't care.

Often the restriction is about ease of access to a back in. We like a challenge. Never had to give up getting into a site. Too bullheaded for that & I have an excellent spotter with a radio & good hand signals.

All of this is not to say that size does not matter. It does. Anything less than 30' can fit most anywhere. Go past 30 & site availability starts to drop off. The longer you go the steeper the curve of being too big.

I've been very curious about the 50' limit I see in many park campgrounds. The warnings I have read state that this is for TOTAL vehicle length, including tow vehicle. If this is the case, then the longest thing I can tow with my 1/2 ton pickup is about 30' and the trailer the wife wants is 33'.

Not sure if that extra 2-3' makes everything a no go or not. I watched one video where they state that anything longer than 50' couldn't even get into certain parks...

I think I misunderstood the OP's post. If considering the advertised length limit in a campground (wherever that may be), use the actual length of your camper, bumper to hitch. If you use the actual length of your camper and tow vehicle combined, you're really limiting yourself. If a campground advertises the length of a specific camp site ... say ... 30 feet, more than likely you'll have no problem getting a 31 foot trailer in that site and still have room to park your tow vehicle. Although the tow vehicle may have to be parked parallel to the road in front of the trailer.

But there again, every campground and every camp site in those campgrounds are different. But for the most part, if you look for sites longer than your trailer (actual length), you'll most likely not have any problems. The problem arises when there are trees or other campers who park their cars in your way, making it very awkward getting into the spot. But, regardless of site length, that's always a given risk.

rvshrinker wrote:
Our goal is to be able to get into most National Park and Forest Service campgounds. Many have a limit of '27 feet'. So what does that mean?

It means many different things.

Some national parks and forest service campgrounds do not have any spots which are longer than 27 feet from the obstruction at the back of the campsite to the road.

Some spots have rocks or trees at the back of the spot so that you cannot overhang the back of the trailer past the paved or marked part of the spot. Some spots have room for me to hang 12 feet of my trailer behind the rear tires over the grass/ behind the camping spot.

We've visited some campgrounds where the RV parking spots are parallel to the campground road - but with our 14' total width with the slides on both sides of the trailer open - we could not camp there even though the length is sufficient for my 62' total length.

Some campgrounds, especially US Forest Service, have plenty of large spots, but the barely improved road to get to the campground has turns too tight or with too little clearance for a truck and 28 ft long trailer to get into the campground.

One National Monument in Arizona has a 27 foot limit. While near that NM, we drove down - and they are right, the sharp turn to get into the campground doesn't have clearance for any a larger tow vehicle/ trailer combination to get into the campground. It's even tight for a 27 foot long Class C.

One NM and a different NP in Utah both advertise a 27 foot limit. I could easily pull my 36 ft trailer into both campgrounds, but neither has a space long enough for me to park the trailer, and if they did, the truck would have to be parked halfway across the CG in overflow parking.

You need to know several measurements. And measure then yourself.

Total trailer length - from the tip of the tongue to the end of the rear bumper, or anything extending out at the rear.

Total rig length - from the front tip of the truck to the very rear of the trailer

Length behind the trailer wheels - from the back of the rear tires to the very back of the trailer.

Also know your exact height / clearance and train the person helping you backing up to look up for tree limbs and other obstructions.

Lastly - Carry a 50' tape measure with you to the dealer lot and measure the trailers yourself. DO NOT TRUST A SALESMAN OR BROCHURE for a total length.

A trailer with 28-29 feet tip of the tongue to the rear measurement will likely fit into most of the campgrounds you want to visit.

But I'm sure you will find one where you can't get in.

As to why those campgrounds are so small.

Most were built initially before WWII or in the 1950. People didn't bring long RVs to those campgrounds.

There are many other priorities within the Department of the Interior and the Department of Agriculture (National Forests) for spending than upgrading campgrounds to fit modern RVs.

There is quite a debate about not allowing big modern RVs into many national parks, and many others simply don't have the infrastructure support to allow campgrounds with 30 amp or 50 amp power, the water supply or sewage systems to support water and sewer hookups.

Only the US Army Corps of Engineers has put some priority into upgrading their campgrounds with utilities for modern RVs, but even they have budget issues.

The Fort Worth District of the COE suffered several million dollars of damage to their campgrounds in 2015 and 2016 floods. That is all of Texas except two lakes on the Red River or near the Red River.

Some campgrounds were still waiting funding to repair electrical and water systems which were under water for months.

Our goal is to be able to get into most National Park and Forest Service campgounds. Many have a limit of '27 feet'. So what does that mean? For instance I looked at a Nash 25C but it is 25 feet interior, closer to 28' exterior. Or an ORV 23DBS, which is 28' exterior.

Trying to find a bunk model that also fits in these spots. Wanted to avoid fifth wheel to preserve bed space for gear.

Not only are model numbers of RVs not accurate in terms of their length, but sizes of RVs that can or can't fit into a site as listed by state or federal entities is usually inaccurate as well. I have seen monster size rigs crammed into sites and smaller TT's that have more than twice the space they require to fit their RVs.

For the most part, if your main living cabin is 25' or shorter, you will find sites in most any government run park. When we want to reserve a smaller site just to get into a park we say our box length, when attempting to get a larger site with more space we list ball to bumper length. Private parks are more stringent with actual lengths.

If it's the highway patrol that's measuring, it's generally from the pin to the back end (or, for a combined length, from the front of the tow vehicle to the back of the towed vehicle). Sometimes things are based on the pin to axle length or other measurements, but that's usually pretty clearly specified.

The manufacturer model numbers may or may not relate to any particular measurement, and if they do it's often in a rather loose fashion. I think it's best to think of them simply as model numbers and pretend that they do not have anything to do with length. My Coachmen Santara 315QB is just about exactly 32 feet long overall, front bumper to back bumper. (Since it's a class C motorhome, there is no hitch coupler or tongue to worry about.)

Looking up the Alabama laws here, I think the AAA guide is wrong. It looks to me like the limit for a vehicle (trailer or otherwise) is 40 feet, without any general legal limit on combined lengths that would apply to a travel trailer. A call to the DMV or equivalent should give more official information.

I have a 2005 Montana 2955RL. Sold as a 29 footer but if you measure bumper to pin it's 33 feet.

I measure from tip of tongue to the tip of rear bumper plus spare tire

rvshrinker asks "How is a travel trailer length measured?"
Sorry but I cannot resist this:
With a tape measure!!