看了一下，好象是三段：

http://www.nps.gov/yell/planvisit/orientation/travel/roadclos.htm

看了一下，好象是三段：

1. Chittenden to Canyon

"This road segment will continue to be closed to visitor traffic until August 19 including holidays, then open until October 10 with half-hour delays." 就是说，八月19号、十月之前是通的，对吧？不太放心自己的阅读理解了。那么前面那位说的 "Tower Junction/Fall 处在修路，玩儿后要原路退回到Mammoth Hot Springs"的情况到九月就好了喽。


2. Sylvan Pass to East Entrance

"This road segment will have road construction from opening (May 6-weather permitting) through October. It will be open 8:00 a.m.- 8:00 p.m. with possible half hour delays and closed nightly 8:00 p.m - 8:00 a.m"
这段好象不严重，最少没有关掉。


3. Beartooth Highway
"This road segment is outside of Yellowstone National Park boundaries" 哈哈，跟我是没关了。

不过还是要在去之前打电话问问清楚："For current road information, call: 307-344-7381"