Exit Chiang Mai Old City via Thapae gate heading east on Thapae Road. Cross the bridge over the Ping River and remain straight as it becomes Charoen Muang Road (Route 1006).
Turn left onto the Inner Ring Road (Route 11), heading counter-clockwise.
Turn right on Route 1001 (north-bound) and drive about 50 km.
You will begin seeing signs (in English) for the Mae Ngat Dam. Follow these signs and turn left onto Route 1323.
The road twists and turns. At the T-intersection, follow the Mae Ngat Dam sign and turn right.
A few hundred meters you’ll see a brown Sri Lanna National Park sign. Turn left here.
Follow a second Sri Lanna National Park sign as the road curves right and then slightly left.
At the T-intersection, there will be another Sri Lanna National Park Sign pointing left. Follow this down a few hundred meters until the park entrance, hanging left at the Y in the road at the “Entrance” sign.