Here’s a more complete update regarding the road closure on Dec 18th from http://www.nationalparksgallery.com/park_news/6161
Wednesday, Dec 26, 2007
A series of winter storms brought snow and ice to the park during the week of December 18th and caused several rockslides along Northside Drive between Camp 4 and the El Capitan crossover. A large boulder was reported on the roadway around 4 p.m. that afternoon, the product of a rock fall that occurred near the cliff face of Middle Brother in Yosemite Valley. The drive was immediately closed. Since vehicles couldn’t exit from the road due to a large downed oak tree at El Capitan straightaway, they had to be escorted out through a construction road closure. There were no injuries, but employees leaving work were inconvenienced. Staff from roads and trails, the sign shop and visitor protection opened Southside Drive for two-way traffic. Northside Drive remained closed and was monitored. Another rockfall occurred that night, and a second large rockslide occurred in the closed area around 3:30 p.m. on December 19th – but did not reach the road. The closure remains in effect until further notice. The valley remains open to all traffic via Southside Drive.