There are not many 100 mile races in Nepal, or anything nearing 170 km! Lots of reasons why! It’s expensive to organise such a long race and for that you need a lot of participants to cover the costs, or perhaps lots of awesome & dedicated volunteers to make it work on bootstrap style. That’s the case here and expect to see only one 100 mile trail race per year in Nepal going around the Kathmandu Valley Rim.
See also: all events, single day ultra trail races, stage races or multi-day trail races in Nepal, fastpacking trips, 100 miles races in Nepal, and finally trail marathons in Nepal.