Installing dryer vent on landmark 365 Newport

We are getting ready to install a dryer vent
and have to cut a hole in the 5th wheel for the vent. Can the markings be trusted where it is located?

In a word, no.
At about two inches above the floor drill a series of exploratory holes using a small drill bit.
Low so that your holes are not visible, two inches above the floor so you are not drilling into the aluminum sill square tubing and directly below your intended location of the vent hole.

Peace
Dave

Thank you for the advice. We will do that.

I used a small hole where Heartland marked the dry vent and probed with a metel coat hanger. Having not hit anything other than the foam insulation, I then used a stud finder and marked studs. All looked clear, so I trusted myself and drilled the hole...perfect! No issues.

You can watch my video tips on installing both the washer and dryer by clicking on the link below...hope it gives you some insights on what to expect.
https://youtu.be/g1wLohuKu-M