A section of Sir Francis Drake Boulevard on Olema Hill that collapsed during a late-winter storm in 2011 is finally repaired, the Marin County Department of Public Works announced last week. The nearly $600,000 project, which began in late June after motorists for more than two years tolerated long weekend waits behind provisional stop signs, or chose the alternate route over the hill, through Nicasio, included the construction of a 212-foot retaining wall. Federal funds,…