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, including emergency relief funds, covered almost 90 percent of the project’s cost, county civil engineer Ernest Klock said. The time lag between the initial damage and the repair resulted from the fact that the project had to comply with national environmental law, which required extensive environmental review, including biological, historical and archeological studies. Concerns raised about the federally threatened northern spotted owl were countered by data provided by the National Park Service showing that no owl pairs were “close enough to be disturbed by the construction activities”; additionally, the repair was scheduled so as not to coincide with the birds’ nesting season. “We have shared in the public’s frustration with the long-standing lane closure and express our sincere thanks for the epic patience people have shown,” public works director Bob Beaumont said in a press release.