Forage production for wintering livestock in Alaska has long been a problem where cleared land is limited. In the vicinity of the Knik Arm of Cook Inlet there are tide flats where native grasses grow in such abundance that they are utilized for hay. To determine the relative feeding value of this tide flat hay as compared with other locally-grown roughages for wintering pregnant ewes, the Matanuska Experiment Station carried out a series of five one-year feeding trials. The tests were conducted for an xverage of 151 days’ feeding period each year, using the bred ewes of the Station flock of pure-bred Hampshires. Results were based on the condition of the ewes at the contusion of each year’s trial, on the size and vigor of the lambs, on ihe weight and quality of the fleece and on the cost of the respective rations over the five-year period.