Environmental organizations filed a lawsuit Tuesday that seeks to overturn a plan for public lands in southwestern Colorado, saying it was approved while William Perry Pendley headed the U.S. Bureau of Land Management and a federal court has ruled that his tenure was unlawful. The lawsuit, filed in U.S. District Court in Colorado, amends an earlier complaint that challenged the BLM’s approval of a plan to open up more public land in the southwest part of the state to oil and gas drilling.