Driving from Spokane, WA to Sumas, WA!!! HELP ASAP!!! LEAVING TOM!!!?

I'm driving from Spokane, WA to Sumas, WA (the US/Canadian border tomorrow). As I have already driven from Indiana to Washington, I have passed through many mountain ranges that I found quite treacherous. I'm wondering if the drive from Spokane to Sumas involves any mountains/mountains ranges. If so, is it hard to drive? Will I have to drive up and down mountains as I did today from Indie to Washington? PLEASE RESPOND ASAP!!! I'LL BE LEAVING TOMORROW!!!!!