8/26/06 Devils Postpile National Monument

Devils Postpile National Monument位於加州的Mammoth Lakes旁邊，原本是屬於優勝美地國家公園的一部份。然而，當黃金在這一區被發現之後，特殊利益的採礦組織要求將地盤重新劃線，使得Devils Postpile這一區變成了公共的土地。再事隔幾年，當地人更有計劃在這兒建水壩，不僅要直接將整個Postpile炸掉，更會破壞附近的生態。環境保育人士上書給總統，使得1911年這一區又回規聯邦政府所接管。

Devils Postpile National Monument is located right next to Mammoth Lakes, California.  Originally part of Yosemite National Park, the boundaries were redrawn at the urge of local miners, and the Devils Postpile was again public land.  Later on, plans were drawn up to blast the Postpile to use them as a dam.   Environmentalists persuaded president Howard Taft to put the Postpile and Rainbow Falls under federal protection in 1911, where it has remained a NPS unit until today.

Devils Postpile NM只有夏天有開放，通常時間是六月中旬到十月中旬。要前來參觀的朋友，最好先和公園打電話確認。(電話為 (760) 934-2289 )從舊金山灣區到Devils Postpile最近的路，其實是穿過Yosemite NP，而橫跨Yosemite的CA-120道路也剛好這時才開放通行。接著，接US-395往南，然後再接CA-203往 西進Mammoth Lakes就會慢慢看到Devils Postpile NM的路牌。

從六月底到九月初，想要進去Devils Postpile NM這一區的遊客都得在Mammoth Mountain Adventure Center購買Reds Meadow Valley的公車票。這是為了防止夏天入公園的遊客過多而阻塞交通。原本的成人來回票是$7，16歲以下的小孩是$4，不過好像費用要調整了。最新的情形，請參考官方的網站。

Devils Postpile NM is only open during the summers, from mid-June to mid-October.  Please call ahead with the park to confirm.  (The number is  (760) 934-2289 )  Coming from the Bay Area, the quickest route is to pass through Yosemite National Park via CA-120, which also happens to be open during the summer months anyways.  Taking US-395 South towards Mammoth Lakes, and then going West via CA-203, you will see the sign for Devils Postpile NM.

Those who wish to visit the monument during late June to early September must park their cars and purchase tickets to take the Reds Meadow Valley shuttle bus into the park.  This was done in an attempt to thwart the large number of visitors during the summer months that would cause serious traffic congestion and pollution.  The adult roundtrip fare is $7, but there have been plans for a fee increase. 

我們為了可以有一整天逛Devils Postpile，因此在週五晚上就殺過去了，在夜晚的時刻，第一次生平就這樣穿越了Yosemite。在Mammoth Lakes，我們住了一間叫Holiday Haus的motel，不好不壞，該有的都有。

To get a whole day to hike the area, we decided to drive to the area Friday night.  There was not much to see of Yosemite's Tuolomne Meadows and Tioga Pass at night, but nonetheless, it would be our first experience of driving across the park.  We stayed at a budget motel called Holiday Haus, which provided the basic accommodation. 

週六當天，我們先在旁邊的Perry's Italian Cafe吃了一頓豐盛的早餐，再開始決定去健行。
Saturday morning, we decided to treat ourselves to a good full breakfast at Perry's Italian Cafe before we started our hike.

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離Devils Postpile最近的公車站是第六站的ranger station，而走不用0.5 mile就到了。
Devils Postpile can be easily reached from Bus Stop #6, where the monument is just 0.5 miles from the ranger station. 

Devils Postpile 

Devils Postpile的地質結構為basalt(玄武石)，大約在十萬年前，兩英里上游處有玄武熔岩從地底噴發，流出來。由於玄武熔岩的黏質係數 (viscosity)較其他熔岩低，便如同河流一般順勢往下流。它後來遇到阻礙，很有可能是冰磧石(moraine)，而像水庫一樣就靜止，累積有 400英尺之深。而這岩漿的組成非常一致，其他雜質少，加上冷卻既慢又均勻，因此慢慢形成了一根根多角形的石柱，是在岩漿冷卻時體積收縮時，產生出來的空 隙。再，一兩萬年前，流過的冰河流過，剛好將一片給暴露出來，經年累月的風化，也將那原本400英尺的石柱，弄得只剩今天60英尺多。

Basalt lava erupted about 100,000 years ago, flowing downstream for 2 miles, where it was stopped by possibly glacial moraine.  It was estimated that this lava pool was originally 400 feet deep, which is unusual by normal standards.  Because of the uniform composition of the basalt lava and also as important, uniform cooling, cracks formed as the lava solidified, creating polygonal columns.  The shapes that are seen the most are the hexagonal columns.  Later on, about 10,000 years ago, a glacier flowing through carved away one face of the basalt formation and exposed the columns.  Lastly, continual erosion has shortened the 400-ft column to a mere 60-ft column today.

這是另一邊倒下來的石柱的近照

close-up of the basalt columns lying flat 

這是在主要Devils Postpile最上面的石柱的模樣。上面因為長期的風化而被磨得很平。可看出石柱為多角形的柱子，其中又以六角形的柱子最多。

This is a view of the Postpile standing atop of it.  The erosion has made the tops relatively flat, and the polygonal cross-sections of the column can be seen clearly.  

Rainbow Falls

公園裡另一個景點為Rainbow Falls，在Devils Postpile南邊2 mile左右的地方。之所以叫Rainbow Falls，是因為太陽從上面高照的時候，瀑布的水打到下面石頭所濺出來的霧氣，會製造出一道彩虹。

從Devils Postpile那兒要走到Rainbow Falls的路程雖然短，但土質鬆軟，沿路沙土很多，讓行走變得有點困難。另外，這兒的高度的有7500 ft 之高，空氣稀薄，使得走沒幾步就開始在喘。前一陣子才挑戰全長有9 mile之多的Pinnacles National Monument，累的程度，卻很神奇地，反不及來回一半都不到的Rainbow Falls trail。

The other attraction in the park is Rainbow Falls, 2 miles south of the Postpile.  It gets its name because of a rainbow that forms when sunlight hits the mist at the right angle, created by the waterfall hitting the bottom rocks.   The trail to Rainbow Falls from the Postpile is nor particularly long, but it is loose sand and gravel, and the high elevation of 7500 ft can make it challenging for some people.  Certainly we were out of breath early on, which we were very puzzled at first, since the Pinnacles National Monument hike we did earlier in the month that was significantly longer did not seem as tiring as this one. 

trail 上會先經過一片歷經火災催殘的森林。

trail to Rainbow Falls leading through a forest devasted by fire

騎著馬的遊客，會比我們徒步行走的人輕鬆許多

visitors taking the easy way out by horseback riding

Rainbow Falls。這裡是個熱門的照相景點，得跟一群人搶照相的機會。可看到瀑布下面旁邊的岩石凹進去。這是因為上面和下面岩石的成份不同，硬度也不同。河水長期流過，會將下面硬度比較低的石頭慢侵蝕掉。

Not sure why, but this is a popular photo spot, where you need to fight your way against other tourists to get a decent shot.  A little cave can be seen next to the bottom of the waterfall.  This is because the high and lower layers of rock have different composition and hardness.  As water runs through, it will erode away the lower softer layers.

走到了Rainbow Falls，我們接著是走到比較近的九號公車站，坐回外面拿車。Mammoth Lakes雖然說是南加人愛來的冬天滑雪勝地，不過對於不愛滑雪的北加人來說，夏天這一帶也是有多處景點是可以參觀的。

After reaching Rainbow Falls, we would hike to Bus stop #9 to take the bus out of the park.  Mammoth Lakes may be a skiing paradise during the summer for the people of Southern California, but someone from Northern California like me is still able to find places to go and things to do here during the summer.


Official Website:
Devils Postpile National Monument