Since a picture is worth a thousand words, this one sums it up:

Yep, the truck overheated going up a 12% grade on State Highway 9N heading east into Elizabethtown, New York. So it turns out that my anxiety and my hand-wringing were well founded, and I should have heeded those instincts more closely!
On the way up the hill, I knew the engine wasn’t happy, but the gauge wasn’t showing it was hot. I was chugging along, trying to maintain 25 mph, and got to the top where I thought things would calm down a little. Then the engine just stopped. You know how the power steering and brakes go out when the engine stops? Scary. I felt lucky to be able to get over to the side of the road and park on the teeny tiny shoulder, before the highway made a big downhill run which might have been disastrous. I have to admit that my heart was pounding. Some of you have called me brave to do this? HA!
And once I’d pulled over, I looked at my phone to make a call – and there was no cell service. Murphy’s Law at work.
The good news is 1) I was able to unhook my car, which might have been impossible because I was on a downhill slope which can create too much forward pressure on the hitch, 2) I have a roadside assistance policy for the RV with Good Sam, which includes towing, and 3) I’m in a gorgeous part of the country – there are worse places to break down. Always trying to look at the positive!!
As planned, I had taken the scenic route, which starts on Route 3 out of Carthage, NY, and winds through the Adirondacks to Saranac Lake. From there, I took Route 86 and then 73 to Keene, and then got on 9N to Elizabethtown, headed for Vermont. I was doing really well and feeling rather cocky that I’d made it across the Adirondacks, when I hit that steep grade. I thought I would at least be able to make it to the town to stop and get checked, but it was not to be.
Actually, I made it to Elizabethtown with my car, and fortunately, Verizon cell service worked great there. It was probably about 10:30 am when I broke down, and about 3 pm by the time the tow truck got to my rig and hooked me up, ready to head about 40 miles to Saranac Lake – back the way I came.

I felt fortunate to find a room at a cheap hotel right near the garage. There was no mechanic on duty yesterday, but I walked over to the shop this morning (Monday). The long-awaited call came at 6 pm this evening, reporting that they had to replace a clamp. The engine had severely overheated, and the old clamp failed, which released the hose and all the anti-freeze. They test-drove it, and the engine is just fine now. Whew!! It certainly could have been far worse.
So now the question is: which route do I take to Vermont? Well, I did my research, and found a terrific resource – an e-book for $25 called Mountain Directory which outlines all the above-average grades on roads across the country. And yes, that little stretch of road where I got stuck is in the book. So I was able to plan my 100 mile trip tomorrow to avoid steep grades, and I’ll know better for next time. Wish me luck!!