This 225-sq-km park (0 5351 9216-7; www.dnp.go.th; admission 400B) receives around 10, 000 visitors a year, making it one of northern Thailand’s least visited. It ranges in elevation from 350m at the bamboo forest lowlands to 1363m at the pine-studded summit of Doi Khun Tan. Wildflowers, including orchids, ginger and lilies, are abundant. At the park headquarters there are maps of well-marked trails that range from short walks around the headquarters’ vicinity to trails covering the mountain’s four peaks; there’s also a trail to Nam Tok Tat Moei (7km round trip). Thailand’s longest train tunnel (1352m), which opened in 1921 after six years of manual labour by thousands of Lao workers (several of whom are said to have been killed by tigers), intersects the mountain slope.
Bungalows (0 2562 0760; r 400B, bungalows 4/6/9 people 1500/2200/2700B) are available near the park headquarters. You can pitch your own tent for 30B or rent a two-person tent for 150B. There is a restaurant by the bungalows. The park is very popular on cool season weekends.
This park is unique in that the main access is from the Khun Tan train station (15B, 1½ hours, daily trains from Chiang Mai at 6.45am, 9.20am and 3.40pm). Once at the Khun Tan station, cross the tracks and follow a steep, marked path 1.3km to the park headquarters. By car take the Chiang Mai–Lampang highway to the Mae Tha turn-off, then follow signs along a steep unpaved road for 18km.