Aspen managed the preparation of an EIR/EIS for the highly controversial 150-mile high-voltage Sunrise Powerlink Transmission Project, under the direction of the BLM (El Centro Field Office) and CPUC. Aspen developed a wide range of alternatives including 300 miles of transmission corridor alternatives and other electricity generation alternatives that would achieve the project's objective to import power, including renewable energy, from the Imperial Valley into San Diego County. The proposed project crossed seven jurisdictions including BLM, unincorporated Imperial County, Anza-Borrego Desert State Park-California Department of Parks and Recreation, unincorporated San Diego County, Department of Defense -Marine Corps Air Station Miramar, the City of San Diego, and the City of Poway. In addition, many of the alternative routes would be located on United States Forest Service lands within Cleveland National Forest. Aspen managed a team of 18 subconsultants to fully analyze 27 alternatives at the same level of detail as the proposed project.

Over 6,000 copies of the Notice of Preparation were mailed to interested parties, including 236 representatives of over 65 different agencies, 52 environmental groups, 64 tribal government representatives, and 41 elected officials. The first round of scoping meetings included 7 public meetings with over 260 people in attendance and an additional 12 agency meetings, and the First Scoping Report summarized 323 comments.

The second round of scoping meetings on Alternatives included 8 additional meetings with over 600 people in attendance, and the Second Scoping Report summarized over 445 comments. After the Cleveland National Forest identified a new alternative through the forest, a New Alternative Notice was mailed and an additional comment period was held with 90 comments received. The printed Draft EIR/EIS was a 7,000-page, 6-volume document. The Draft Notice of Availability was mailed to 13,616 people and published in the Federal Register. Public meetings were held on the Draft EIR/EIS and included: 11 informal workshops, 5 formal public hearings, and two additional en banc public hearings that were attended by four of the five CPUC commissioners.

As a result of new information about the project furnished by the applicant late in the process, a Recirculated Draft EIR/Supplemental Draft EIS was prepared and two additional public informational workshops were held prior to publication of the Final EIR/EIS. The Final EIR/EIS responded to 3,000 pages of comment letters on the Draft EIR/EIS and nearly 900 pages of comments on the RDEIR/SDEIS. Aspen assisted the CPUC with Decision Support, including writing the CEQA Findings of Fact and portions of the Proposed Decision and has assisted with the appeals process. Aspen also wrote the draft Record of Decision for the BLM and has assisted with the appeals process.