Grand Canyon Protection Act of 1991

Grand Canyon Protection Act of 1991 - Requires the Secretary of the Interior to operate Glen Canyon Dam in such a manner as to protect, mitigate adverse impacts to, and improve the values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established.

Directs the Secretary to: (1) develop a plan for operating the Dam on an interim basis to protect, mitigate adverse effects to, and improve the condition of the natural, recreational, and cultural resources of the Park and Recreation Area; and (2) implement the plan on the earlier of September 1, 1991, or the date of cessation of research flows used for preparing an environmental impact statement ordered by the Secretary. Enumerates certain objectives to be included in the plan as implemented, including noninterference with the water storage and delivery functions of the Dam, the minimization of adverse environmental impacts of the Dam operations on the downstream Park and Recreation Area, and adjustment and monitoring of sufficient water flows downstream from the Dam. Directs the Secretary to consult with appropriate agencies of the Department of the Interior, the Secretary of Energy, the Governors of affected States, and affected Indian tribes in the development and implementation of the plan. Authorizes the Secretary to deviate from the plan if found necessary and in the public interest.

Requires the Secretary to complete a final Glen Canyon Dam environmental impact statement within three years after enactment of this Act. Directs the Secretary to: (1) adopt criteria and operating plans separate from those specified under the Colorado River Basin Project Act of 1968; and (2) ensure that the Dam is operated in a manner consistent with the protection of the Park and Recreation Area.

Requires the Secretary to establish and implement long-term monitoring requirements to assure that the Dam is operated in a manner consistent with the protection of the Park and the Recreation Area downstream.

Authorizes appropriations.