ann : I like www.swissvistas.com , search 'festivals' by month.
Sept 11-20 is Oktoberfest in Luzern
Sept 11-12 Traditional Alpabfahrt in Sumiswald, but travel is 2hr 45 min or more with 4-5 changes from Wengen :-((.
Sept 15 in nearby Spiez is their Winefest and Autumn market (sounds like fun).
Saturday, Sept 6- Kandersteg/Ueschinental cow, calf and goat descent, but again, a decent amount of travel involved.
I think Saanen is September 15- you could investigate further.
It took me over 10 trips before I happened into my first "cow event" last year. Now I'm hooked! ;-)).

Is there an easy way to see if there are any cow descents taking place while we are in the area - 11th to 16th of September, say within an hour of Wengen?.>

Gimmelwald, perched high above the Lauterbrunnen Valley is about an hour or so via public transportation from Wengen (train to Lauterbrunnen - aerial cable way to Gimmelwald - it is famous for its return of the cows and being a nigher altitude than many places the cows may come home early in the fall - perhaps.

Again contact the Gimmelwald tourist folks to check on dates:

http://www.gimmelwald.ch/e/main.htm

And Gimmelwald is an exception place - a farming hamlet out in the middle of nowhere or so it seems - highly recommend the trip to Gimmelwald and nearby Murren - the aerial cable ways up there - from Lauterbrunnen To Grutschalp or Stechleberg to Gimmelwald/Murren are absolutely thrilling - like being in an airplane it seems.

Ah thanks for all the tips. I will be sending out some emails. All sounds very fun and certainly would add to the Swiss experience - I have a sense that I too will become hooked on this country and will want to keep coming back.

I'll be interested in any reports about cows returning you hopefully will encounter.

I have a sense that I too will become hooked on this country and will want to keep coming back.>

IF you can afford it after undergoing sticket shock your first visit.