Wildlife in the north of Thailand

Hoping to hear some good suggestions too. But I can't help you. The only larger mammal I've seen in the North was Goral at Doi Inthanon.

Even though I did not see anything that I remember, maybe Sri Lanna national park could be interesting. It's just a guess/ feeling I got from my short visit.

And for snakes. I did a short night walk on a trail from the camping ground along the waterfalls in Doi Luang national park and found 4 Pope's Pit Vipers (could be these days it might be considered a different species, but anyway beautiful green pit vipers with a bright red ventral line all the way to the eye.)

That's my little experience in the North.

I did enjoy climbing the mountains of Chiang Dao, even without seeing any wildlife.

But anyway, I'm afraid you ended up in the wrong region... wildlife-wise. But I hope I'm wrong

I think I need to dissagree a little with that. At least, the Khao Sok part. Even though very little experienced, I've been to Khao Sok once (4 years ago). Got to see macaques, langurs, wild boar, slow loris, palm civet, mouse deer, and heard elephants, though I can imagine that it's not the easiest place to come accross elephants.
And not too long ago the news was showing grazing Gaurs in open areas on the shores of the big reservoir.
I do agree that it's easier to see something in Khao Yai. But I think the North is much worse than Khao Sok.

Khao Phanom Bencha, only remember seeing a slow loris, and 3 poachers... it's a long story, something about getting lost, walking into poachers in the dark, and them helping me out of the jungle rather than shooting me and/ or the slow loris that we came accross... friendly guys, and I was 'happy' to meet them in a rather desperate situation. Saved me from spending an unprepared night in a very dark jungle.
No idea what they were after.

I have no experience with the North, Burma or Laos but have just posted something in the "library" section of this forum that may help you a little in your search, the "Red List" and "Thailand Mammals Listing" posts should help.

For the sake of ease, you should probably be heading for somewhere with Elephants. Discount Sanctuaries because there are access restrictions that can seriously complicate a trip plan. You don't want some complication killing off your trip if its a major trip for you. Stick to National Parks. The closest to you that I have been to and you would have a "chance" of seeing something big would be Mae Wong, Nam Nao (a side trip to Phu Khieo would be worth considering - its a sanctuary but anyone can enter the main section after 8 a.m.) and Thung Salaeng Luang. Local support and a guide may be difficult to arrange.

BUT there are so many variables and as everyone here will attest there is much much more chance you will not see something than there is that you will see something (as far as big mammals go).

In terms of central Thailand, then IMHO your best chance to get local support, no access issues and a chance at a large mammal are Khao Yai, Pang Sida, Kaeng Krachan and Kui Buri. Of those four, Kui Buri is the only place I have been were I have seen a big mammal on every visit. You could do Kui Buri and Kaeng Krachan on the same trip as they are in the same location. There is another post in the forum in which Jonathan gives a very good description of Kui Buri and how to visit there. There's also lots posted on Kaeng Krachan in other posts.

I would personally recommend a trip to Kaeng Krachan and Kui Buri (note: Kaeng Krachan is closed until November), alternatively a trip to Khao Yai but visiting the main park area and one of the substations (or Pang Sida) known for Gaur sightings. IMHO that would be your best chance of actually seeing something big in Thailand. You will have a better chance of seeing something when the rainy season is over. But keep in mind you may not see anything. All of these parks are full of animals but the nature of their survival is to avoid being seen, and the nature of the forest is to hide everything from view.

I go to these places most weekends but have developed a somewhat holistic attitude to being in the forest, I just enjoy being there, in the rawness and complication of the forest itself. Developing an interest in Arthropods virtually guarantees, like for birders also, that I will see something that will interest me, when its not dry dry.. Mammals are icing on the cake. And that cake is sometimes a rare luxury.

You will need to think about logistics and possibly a guide also.

Keep in mind, of course, that to get to Kui Buri from Pai is a HUGE drive and not doable in a day safely. Kaeng Krachan is 3-3.5 hours from Bangkok and Kui Buri is about 4.5/5 hours. Pai to Bangkok must be about 14 hours (??).