From Canada:
For downtown Blaine take I-5 exit 276, the first exit immediately after the Peace Arch border crossing.
For Birch Bay or Semiahmoo take I-5 exit 276 or 270.
From Seattle/Bellingham, Northbound I-5:
For Birch Bay take exit 270.  For Semiahmoo take exit 274. For Blaine take exits 274, 275 or 276.
To Birch Bay From 1-5 heading south:
Take exit 270.
From Blaine to Birch Bay:
Follow Peace Portal Drive south to Bell Road. Turn right, cross over railroad tracks and follow Blaine Road to right on Drayton Harbor Road (Yorky’s Market), follow to Harborview Road (bends to the left) straight on Harborview Road to Birch Bay (Birch Bay Waterslides on left).
To Semiahamoo From I-5:
Take exits 276 or 270, follow signs.