There are indeed a lot of choices. And it can indeed be confusing.
For the Muir Traila 211-mile route through three national parks (Yosemite, Kings Canyon, and Sequoia)what youre really after is semi-emergency wear as a hedge against afternoon thunderstorms. And these days there are lots of well-priced pieces that fill that role admirably. Best-known is Marmots PreCip Jacket ($99). Its a perfectly functional rain jacket that, while not as breathable or durable as more expensive pieces, is just perfect for those occasional downpours. Add a pair of PreCip Pants for $90, and youve got a decent rain suit for under $200.
For a longer-term investment, I like REIs Taku Jacket ($199). It uses a proprietary laminate to give you a jacket with excellent waterproofness, adequate breathability, and good durability. The Taku also uses stretchy fabric in the hood and around the torso, so its a good piece for reaching and scrambling. And its light and compressible.
You also can get into Gore-Tex for $200, in a piece such as Mountain Hardwears Typhoon Jacket, which uses Gores PacLite material.
After that, well, its a matter of what you care to spend. The Westcomb Specter LT ($300) is an excellent lightweight jacket that uses eVent, a material that I think is superior to Gore-Tex in some regards. Its a tough and functional piecefine for your Muir hike, excellent for future climbs. And its the kind of jacket you can wear during long days of rain or snow.
Or, there is Arc'teryxs Alpha LT ($490), which uses Gores new light and very tough Pro Shell material. This jacket is a real investment, and I do like the Pro Shell fabric. And it weighs just 13 ounces! But yikes that price!
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