Timberline Trail is a good one with lots of options.
Zig Zag Mountain(s) has good views as does Tom Dick and Harry Mt.
Cooper Spur Trail from the ski area would give you great views and good vertical.
There’s some great trail runs on the Oregon side of the Columbia River Gorge and you can put together some solid vertical but I’m not sure if all the trails are open after the fire a couple years ago.
If you’re in the city, head to Forest Park.