Yes

From the AA web site

Aadvantage - Advantage Member Guide - Earning miles - Earning miles on airlines:

Earn a minimum of 500 AAdvantage miles each time you purchase and fly on a published eligible fare ticket on Alaska Airlines and Horizon Airlines. Qualifying mileage counts toward AAdvantage Executive PlatinumŽ, AAdvantage PlatinumŽ, and AAdvantage GoldŽ status and bonuses. To attain AAdvantage elite status, member must fly on at least four American Airlines or American Eagle flights within the qualifying year. Cooperative service flights operated by carriers other than American Airlines may not be eligible for mileage accrual.