The most direct approach into the national park from the south is over Chief Mountain International Hwy. (SR 17/Hwy. 6) from Glacier National Park in Montana; the park also is accessible via Hwy. 5 from Cardston or Hwy. 6 from Pincher Creek. Covering 505 square kilometres (195 sq. mi.), Waterton Lakes National Park adjoins Glacier National Park. Together the two parks form Waterton-Glacier International Peace Park. The Chief Mountain border crossing customs office is open daily 7 a.m.-10 p.m., June 1-Sept. 1; 9-6, Victoria Day weekend-May 31 and Sept. 2-30. Learn More...