Mid November to March 1 is your best bet. It also depends on the weather any particular day. On a cool or cloudy day, you will most likely only see a few monarchs in comparison to the huge numbers on a warm sunny day. I always check the forecast before deciding which day to go.

I would 100% recommend getting a horse most of the way. I didn't time it but we were on the horse for at least 30 minutes up hill! Some people did walk it but I think I would have died - however I am quite dramatic!!!!!! Once you get to the place where you 'park' the horse there is a steep walk to get to the top where the main bulk of butterflies are. I got most of my best photos by where the horses were so you don't have to go up further on foot but it is worth it, just give it a go and take your time. However, the butterflies are all around the area, even by the roadside, so you don't necessarily need to go to the top, however it is spectacular if you do. The ground is dusty at the top where the Butterflies were so stable footwear with a grip would be recommended. I wore my trainers and it was fine. Take plenty of water with you as it is so hot (January 20 for someone based in Glasgow - so it may not be that hot for you depending where you come from) and maybe a scarf to cover your mouth as at certain points as it got quite dusty. We didn't go with an organised tour, as it was simple enough and a lot cheaper to organise ourselves. If you are worried maybe look into something organised? I hope this helps 😀