(a) Upon receipt of a request to amend the plan map or upon determining to amend the map on its own initiative, the agency will provide notice of receipt of the request, or notice of the determination, and a brief description of the amendment requested or contemplated to the Adirondack Park local government review board, the chairman of the county planning board, if any, the chairman of the appropriate regional planning board, and to the chief elected officer, clerk and planning board chairman, if any, of the local government wherein the land is located, and invite their comments.

(b) The agency will act within 120 days of receipt of a request; however, if it determines to hold a public hearing on the request, it shall schedule the hearing within 90 days of receipt of the request and shall act within 60 days of the close of the hearing. If a request is received when snow cover or ground conditions prevent field investigation, or in the case of a request or series of related requests exceeding 500 acres, the time periods shall be extended an additional 90 days or until adequate field inspection is possible, whichever is sooner. Any time period may be waived or extended by written request of the applicant or the agency on consent of the other; provided, however, that the agency shall not act until Part 586 of these regulations has been complied with.