Highway 26 from Portland to Government Camp then just a few more miles till you see the sign for Trillium Lake. Follow the road for 2 miles and you will come to this view point.
Trillium lake rec area has a limited season for motorized cars and trucks. They usually close the gate to the road as soon as snow starts piling up and then it usually reopens about mid May depending on the weather. You can always ski, hike or snowshoe down to the lake as well.
Amazing lenticular clouds at sunrise over Mount Hood and Trillium lake