This is a nice trek that offers very good views of Nanda Devi. A permit is needed from the SDM office in Munsiary but it is easy to obtain, even for foreigners, and free of charge just requiring a bit of leg work to make copies and drop off a copy of the permit at he ITBP post across town. There are no passes and the elevations are relatively low by Himalayan standards only a little over 4000 m. This trek is probably best done before the monsoon in May-June but I did it in early mid October finishing October 14th. Weather wise it was a great time to trek but it was just about as late as you could do it still relying on the small hotels for food and shelter. When I was going up all of the hotels along the trek were open but when I was going down a number of them had closed. The first part of the trek passes through a gorge with the high mountain views only opening up after Rikot. Of the villages of the upper valley Martoli probably has the best location. Its slightly off the main path take the path up to the left after Rikot and near where the abandon village of Tola sits on the opposite side of the valley. From Martoli you can hike up the slopes above the temple (30-45 minutes) to get a view of both Nanda Devi peaks, Trisul, and Hardeel (four +7000 m peaks). A route to the traditional Nanda Devi East base camp starts from Martoli but you will need at least 2 days of food to do this. Apparently there are some stone shelters you could use if not carrying a tent I did not personally make it up that direction. I went up to the base of Nanda Devi via the Pachu valley. From Pachu I made it up to the base camp in 3 hours but this is relatively fast still it can be done as a day hike. There is a nice camp site one and a half to two hours up the southern side of the valley and a rock shelter a bit further up from the camp site. There are trails on both sides of the valley but the one on southern side is better maintained and has better views of Nanda Devi. Milam is on the opposite side of the river as Pachu unfortunately as of October 2009 the northern most bridge across the Gori Ganga is at Burphu about 1.5 to 2 hours back down the valley from Pachu. If you don't mind the cold and if the river is not too high apparently there is a place just below Milam where it is possible to ford. The ITBP camp at Milam can be a bit annoyingly over zealous but friendly. If they try to compound your camera for your stay in Milam just argue a lot and offer to show you digital pictures when you leave to assure them you didn't take any pictures of the camp (they didn't even bother to check mine when I left), if you have a film camera don't tell them you have a camera. The view from Milam Glacier "zero point" itself is not that great lots of grey rock grey ice and grey water. The approach is better, but for the best view hike up the east side of the valley for about an hour and a half to two hours past "zero point" where you will get a panoramic view of the peaks and see the glacier descending from the slopes of Trisul. The trail is quite good after initially being rather rough. The trail starts where the stream comes down to the glacier from the east near zero point. Cross to the northern side of the stream and climb the steep slope the trail eventually levels off and traverses along the eastern side of the valley high above the glacier.
Do It Yourself Information
If you do this trek in October/November you could still get by with out a tent as there are many abandon houses in which you could sleep but you would need a very good sleeping bag. The main issue would be bringing enough food. If you only have time for either Pachu or Milam I would probably recommend Pachu especially if you only go to zero point at Milam but if you hike up above zero point the two become more comparable. It is still very cheap to trek here with sleeping costing between 25-100 rupees, a thali 30-50 rupees, and a cup of tea for 5 rupees. The accommodation is basic but fine.
People have reported that the SDM office will not issue permits too late or early in the season so if you're planning to do the trek in early May or after mid-November its probably best to try to acquire information locally or through a local agent if the office is issuing permits.