'98 = no Atrac Matt, but very likely has a round dial, even better.
Argentine Pass is likely perfect for what you're looking for... but as many have said there's no telling what kind of snow will still be there. I know you said you don't mind snow but we're talking 6-10' drifts that completely cover the road. Every year, on every trail, someone will bust through most and shovel out some of the drifts on every single mountain trail... May is early for that, it's usually more like June. But who knows what this year will bring.
Be sure to post up when your plans get closer!