Alaska [1] is a very popular summer destination for seniors traveling by cruise ship or RV, and for a surprising number of retirees who move to the state. Alaska Marine Highway ferries offer half-price senior discounts on certain smaller vessels in the summer and on most wintertime sailings. Most museums and some restaurants have discounted rates for those over age 65, and visitors to national parks can get an America the Beautiful Senior Pass that allows entry to all parks for a one-time charge of $10.
Travelers over age 55 should consider joining an Exploritas (formerly Elderhostel, www.exploritas.com [2]) educational adventure, with dozens to choose from in Alaska. AARP (www.aarp.org [3]) also has discounted Alaskan trips and other benefits.
Links:
[1] http://www.moon.com/destinations/alaska
[2] http://www.exploritas.com
[3] http://www.aarp.org