pinniped

I finally read some Tripadvisor reviews (which I always take with a grain of salt), but it does appear that the cabins have heaters. Either way, chilly nights wouldn't bother us: we have tent-camped in near-freezing weather.

A bad Tripadvisor review was upset about spiders. OK, certainly used to those in both tents and cabins. Most reviews good and bad simply talked about how small the units were.

On the plus side, the Old Faithful cabins are being renovated after the 2016 season. When we roll in in late May, they should be pretty fresh...for whatever that's worth.

It doesn't sound like I'd want to spend 4-5 nights in one, but to have 2 nights in the park and minimize total drive time, I think it'll be okay.

Iamnotlost

I stayed in a cabin at Old Faithful in mid-Sept 2012. I am pretty sure there were heaters because the temperature outside was below freezing overnight but I was not cold in the cabin. One thing I learned was to look at the front step when leaving the cabin - a member of the local wildlife left me a rather large present one night!

There is also accommodation (Cedar Lodge) in the Badlands NP and I wished I had stayed there. I ended up camping at the KOA south of the park which wasn't even particularly cheap. The Cedar Lodge breakfasts were good.

I am a self-confessed National Park junkie and manage to extract a lot of information from their websites. I do find it takes quite a long time because they don't always link the pages very sensibly. Keep clicking away and all sorts of hidden info materialises. If they offer the chance to download the Park newspaper that is always useful. The Annual Pass is still an absolute bargain as lots of individual parks have upped their entrance fees.

Give my love to Yellowstone.

MSPeconomist

There was a thread in the Marriott forum within the last several months discussing why there weren't more Marriotts close to national parks. Some hotels and strategies were mentioned that might be useful to the OP, although the conclusion seemed to be that it's mostly ma and pa local motels that are really close to the national parks, with perhaps some very cheap chains (that charge very high rates due to the attraction of the location combined with the cost of operating a lodging establishment that's only open/busy for a short season) in a few locations.

The OP mentioned a Park Pass. Check the website for details, including whether it's attached to people (family) or a vehicle. This year (2016) is a big anniversary for national parks so they'll be packed, but there might be a special price if you can get a pass during 2016 that will cover most of the 2017 season, assuming that they're good for a year from purchase rather than a calendar year.

darthbimmer

The National Parks Pass is valid through the end of the current month in the next calendar year.