Please see (2), below. Generally, adults over the age of 17 who are physically fit are 'qualified'.

AS 26.05.010. Alaska Militia Established.

(a) The militia of the state consists of all able-bodied citizens of the United States and all other able-bodied persons who have declared their intention to become citizens of the United States, who reside in the state, who are at least 17 years of age, and who are eligible for military service under the laws of the United States or this state.
(b) The militia is divided into two classes:
(1) the organized militia, consisting of the Alaska National Guard, the Alaska Naval Militia, and the Alaska State Defense Force; and
(2) the unorganized militia, consisting of all qualified persons available for service but not serving in the organized militia.
(c) The adjutant general may, by regulation, prescribe the maximum age for eligibility in the militia.