Swiss travel pass

Murren is not accepted as a destination on the SBB site so is it possible to buy that one at the airport?

Muerren is spelled with an umlaut over the "u", So either use the umlaut or add and "e" after the "u". Murren does not exist in Switzerland, but Muerren, or Mürren do.

I assume this trip is planed in the near future. I'd go with a 6-day 2nd class pass. You can purchase an upgrade to 1st class for Zurich Airport to Lauterbrunnen and return. There is really no point in having a 1st class pass in Muerren itself, because there is no 1st class section of a cable car or gondola or chairlift. With the Swiss Travel Pass, you are only getting discounts on these lifts anyway.

you spell Mürren incorrectly - there is an umlaut over the U, or can use an "e" after it, Muerren will work. Specifically Mürren BLM if you are coming from Lauterbrunnen.

Try that.

Zürich also has an umlaut, the airport station is - Zürich Flughafen

I was also going to mention the waste of money on the First Class in the mountains

I you are going to be mostly spending time in Mürren the STP is not the best option. On most mountain railways and cable cars the STP does not give free travel, just a 50% discount. So you will be using the STP as a discount card, not a free travel card.

Better get something like the Berner Oberland Pass, which also contains many cable cars and railways. You can get that pass for 4 days. Then you would only need to add Zürich - Bern or Zürich - Luzern depending on how you choose to travel to Mürren.

Are you booked in Muerren or 3 nights or 4 nights? 4 nights means 5 days of travel.

The Swiss pass is for 3 or 6 day

There is a 4-day Swiss Travel Pass.

Thank you to all for the great info! I now know how to type Mürren correctly and will get the train tickets and BO passes.