In an area of outstanding natural beauty, this peak is (was?) a word-of-mouth secret with minimal crowds or touristic tackiness. It is not one of the tallest peaks in Northern Thailand, but its remote location, winding approach roads and final spectacular view makes it a trek worth making. During the months from December to February, the chance of seeing the spectacular sunrise over a sea of clouds is good.
The area is today part of Thailand but the area is traditionally a "Tai-Lao homeland". The border division between Thailand and Laos created by the Mekong River (visible for the eagle-eyed from the summit) is relatively new.
An outstanding array of rolling hills, verdant valleys, and elegant peaks.
Flora and fauna
Farmland and orchards/vineyards turn to bush, scrub, and grass near the summit.
Chilly for Thailand in the morning and pleasantly cool throughout the day.
Driving is evidently the easiest option to get to the area, but be aware of the challenging nature of both the road and the (pickup truck) drivers on it. Cars are available for rent starting at around 1,000 baht per day (plus refundable deposit around 20,000 baht) at Chiang Rai airport. A full tank of petrol (~1,000 baht) will get you there and back safely.
Directions from Chiang Rai (2.5-3 hours)
Leave the city southbound on Rte 1 (Phahonyothin Rd). Take the turn off for Rte 1020 which will lead you south and then east. 1020 eventually splits in a rural town, with a left turn continuing as Rte 1020 and straight on becoming Rte 1021. Follow Rte 1021. You will begin to see signs for Phu Chi Fa and will take a left turn for Rte 1155 before reaching the town of Ngao. This road passes through some incredible scenery but you will need to keep an eye on signs at junctions. Eventually you will come to a checkpoint, keep right. A little further you will reach a T-junction. Take a right, following the signs for Phu Chi Fa Forest Park. From here it is a direct road and you will see signs for the amenities, parking, camping, information, and the viewpoint, i.e., the peak.
Every day, there is a 17 seat minibus bus leaves Chiang Rai for the village of Phu Chi Fa at 1 p.m. As of Feb 2018, the fare is 150 baht one way and 300 baht round trip. The return trip leaves Phu Chi Fa at 9 a.m. next morning. It takes about 2.5 to 3 hours depending on traffic and number of stops. Before this time, there appeared no direct public transport.
For seeing sunrise, there is local transportation at 5 a.m. for 30 baht each way to ride from the village to the park parking lot where you start the 750 m hike to the view point. At other times, it's on foot all the way.
Walk the final 750 m on a dirt path to the summit and be rewarded with the immense beauty of the Thai-Laos border.
During the months from December to February, the chance of seeing the spectacular sunrise over a sea of clouds is good.
Enjoy a traditional song from local children in hill tribe costume as you climb. They will spot you, and those not astonished by your presence (assuming you are not Thai!) start singing - a smile or "sawaadee kaaa(p)" as you pass by is fine, but this is a rare circumstance when rewarding them with a few baht doesn't seem unethical. They are fun and friendly, and fascinated by farangs. Rather than hassling you as they might at Angkor Wat they will return to happily playing shortly and rather than being some cabal of gangsters, the money goes straight to their proud parents, invariably just a few feet away. Those unwilling to support the use of children for income could instead teach them a little of your language or compliment their song (dee dee!) or attire (suay maahk!).
There is a minimal amount of warm clothing and souvenirs available for purchase at the final car park near the summit. Don't pay more than 80 baht for a scarf.
Food is available at several restaurants at the village of Phu Chi Fa. The prices are very reasonable. There is no food available at the park.
The village of Phu Chi Fa has the lodgings, from camping tents, hotel rooms to bungalows. The cost is about 200 baht per tent to 500-800 baht per bungalow. The prices depend on supply and demand and one's bargaining skills. Unfortunately, many of these lodging places are not visible online and cannot be booked in advance through the Internet. However, if you avoid major Thai holidays and weekends, there is plenty of supply for lodging.
As of Feb 2018, brown roofed bungalows at the very top, right (facing uphill) with 2 full beds, TV, hot water, good beds, clean, balcony, even mini fridge, water and instant coffee were 800 baht full price but you can haggle. There is a sign with a phone number you must call, they speak a little English and will meet you. Car next morning to Phucheefa is 60 baht per person nonnegotiable.
There are several other places that cost 500-600 baht and are in much worse condition.
Camping is available at the village of Phu Chi Fa. The cost is about 200 baht per tent depending on supply and demand. The cost is higher during Thai holidays.
There is little choice but to retrace your steps for most of the journey. Taking Rte 1021 eastward rather than westward back to Rte 1020 will take you through Phayao Province, near Phayao itself and to Chiang Mai along back roads in a little under four hours.