July 2007 – The California Department of Transportation proposed widening Highway 101 through Richardson Grove to facilitate access by large trucks.
2007- 2009 – Native American and community organizations expressed strong opposition to the Richardson Grove highway project, arguing that it would threaten both the ancient redwoods of Richardson Grove and the character of Humboldt County as a whole.
October 23, 2009 – The Center filed comments with Caltrans arguing that the agency's environmental review of the project did not meet legal standards.
October 2009 – Thousands of citizens expressed opposition to the agency's plans in response to a Center action alert.
May 19, 2010 – Caltrans filed official notice that the highway-widening project was approved. On the same day, the Center for Biological Diversity and Environmental Protection Information Center vowed an all-out legal challenge of the project.
May 20, 2010 – Caltrans released the final environmental impact report for the project, claiming that it would have no significant environmental impact. Meanwhile, the Center and allies were seeking to have legislators pressure Caltrans to rescind the project.
June 17, 2010 – A coalition of citizens and conservation organizations, including the Center, filed a state lawsuit against Caltrans under the California Environmental Quality Act challenging the project's approval.
September 27, 2010 – The Center, two other environmental-advocacy groups and five individuals filed a federal lawsuit against Caltrans for violating several federal laws due to inadequate environmental review of the highway-widening project.
May 25, 2011 – The Center and a coalition of conservation groups and local residents asked a federal judge to stop California transportation officials from moving ahead with the Richardson Grove project.
July 6, 2011 – A federal judge ordered California state transportation officials to stop work on their plan to cut wider highway lanes through Richardson Grove, granting the injunction sought by the Center and allies.
April 4, 2012 – A federal judge today ordered Caltrans to redo critical aspects of its environmental analysis for the project that would widen and realign Highway 101 through Richardson Grove.
March 2013 – Two-dozen conservation and community organizations, including the Center, joined together to take on Caltrans' irresponsible and damaging highway-widening projects around California.
December 2014 – Caltrans rescinded its approvals for the Richardson Grove highway-widening project. The Center and allies dismissed a lawsuit they filed in federal court in July in exchange for Caltrans abandoning the project approvals and agreeing to restart the environmental review if the agency were to pursue the project. Caltrans was prohibited from any project construction activities by both a 2012 federal court injunction and a state court order.