That's the main thing you should bring on any hike of course. If you are willing to turn around, you don't need any special gear. If you are absolutely stuck on the idea of making it up somewhere, risk goes up dramatically. An ice axe is always good assurance, provided that you know how to use it.
That said, there were only a couple of brief sections of snow when the pictures you saw were taken. The snow avalanches (sloughs really) across the trail and builds up in a couple of spots and those melt out very late, especially because of the northern exposure of this trail. Most of the trail was dry at that time though. Only a couple of spots present real dangers in the sense that there is snow and steep drops.
For whatever reason, the dates on those photos are all messed up. You can always tell what the actual date is on one of my photos by the name which always starts with a six-digit code in the form: yymmdd, so the first snowy picture of the Four Mile Trail begins with 041025 which means it was taken on October 25, 2004. The other one, was thus taken April 27, 2004.
If memory serves, that was after the fairly big snow year of 03-04, so I would guess that is more than average snow for that time of year and probably more than this year (though it's been a pretty good snow year).
As for whether or not the trail was closed, I don't generally go to closed areas and don't recommend it, but I can't say for sure that I never have. I guess in the case of one of those photos, I ducked around the second gate. In the case of the other, it was just after the first storm and my wife had to go up to GP to do maintenance on the composting toilet (yum) and I don't believe the trail was closed at that time.
I've also, by the way, climbed up and skied down Ashcan Alley (a.k.a Le Conte Gully, up behind Le Conte Memorial). I did this on something like April 2 one year and since it's never "open" it's never "closed" either. It might be icy, but it's likely to be just mushy. This is a very dangerous place though, as we found out in October of 2006. Bad juju. But it is also one of the most classic Yosemite ski descents.
So anyway, to the point, there are only a couple of spots where snow accumulates and makes for a trip into the abyss. If you aren't 100% certain of your ability to navigate that section, you should turn around. Just for perspective, I grew up in the snow, had a couple of steep icy sections just on the walk to school, have skied all my life, ice climbed since the late 1970s (though I've quit now). I'm not trying to sound like a know-it-all, but I've learned from taking friends out to do stuff, that snow is a really foreign medium to a lot of people, especially in California where there's lots of snow, but most people don't grow up walking in it every day.
Just remember, it's always better to turn around only to find out that it was really fine than to not turn around and die. Personal story: one day a friend and I went ice climbing. I got to the bottom of a pillar that would have been an easy climb for me, but just felt uneasy. I felt a bit foolish, but I just looked at my partner and said I wasn't up for it today (though I had regularly climbed things much harder). Feeling a bit stupid, I asked to turn around and we did. When we got down and were packing up, we heard a big crash. The whole pillar came down. Might have killed us both if we had climbed it. Didn't feel so much like a chicken after that.
Like the saying goes: Making the summit is optional. Making the basecamp is not.
Always Bring a Willingness to Turn Around
That's the main thing you should bring on any hike of course. If you are willing to turn around, you don't need any special gear. If you are absolutely stuck on the idea of making it up somewhere, risk goes up dramatically. An ice axe is always good assurance, provided that you know how to use it.
That said, there were only a couple of brief sections of snow when the pictures you saw were taken. The snow avalanches (sloughs really) across the trail and builds up in a couple of spots and those melt out very late, especially because of the northern exposure of this trail. Most of the trail was dry at that time though. Only a couple of spots present real dangers in the sense that there is snow and steep drops.
For whatever reason, the dates on those photos are all messed up. You can always tell what the actual date is on one of my photos by the name which always starts with a six-digit code in the form: yymmdd, so the first snowy picture of the Four Mile Trail begins with 041025 which means it was taken on October 25, 2004. The other one, was thus taken April 27, 2004.
If memory serves, that was after the fairly big snow year of 03-04, so I would guess that is more than average snow for that time of year and probably more than this year (though it's been a pretty good snow year).
As for whether or not the trail was closed, I don't generally go to closed areas and don't recommend it, but I can't say for sure that I never have. I guess in the case of one of those photos, I ducked around the second gate. In the case of the other, it was just after the first storm and my wife had to go up to GP to do maintenance on the composting toilet (yum) and I don't believe the trail was closed at that time.
I've also, by the way, climbed up and skied down Ashcan Alley (a.k.a Le Conte Gully, up behind Le Conte Memorial). I did this on something like April 2 one year and since it's never "open" it's never "closed" either. It might be icy, but it's likely to be just mushy. This is a very dangerous place though, as we found out in October of 2006. Bad juju. But it is also one of the most classic Yosemite ski descents.
So anyway, to the point, there are only a couple of spots where snow accumulates and makes for a trip into the abyss. If you aren't 100% certain of your ability to navigate that section, you should turn around. Just for perspective, I grew up in the snow, had a couple of steep icy sections just on the walk to school, have skied all my life, ice climbed since the late 1970s (though I've quit now). I'm not trying to sound like a know-it-all, but I've learned from taking friends out to do stuff, that snow is a really foreign medium to a lot of people, especially in California where there's lots of snow, but most people don't grow up walking in it every day.
Just remember, it's always better to turn around only to find out that it was really fine than to not turn around and die. Personal story: one day a friend and I went ice climbing. I got to the bottom of a pillar that would have been an easy climb for me, but just felt uneasy. I felt a bit foolish, but I just looked at my partner and said I wasn't up for it today (though I had regularly climbed things much harder). Feeling a bit stupid, I asked to turn around and we did. When we got down and were packing up, we heard a big crash. The whole pillar came down. Might have killed us both if we had climbed it. Didn't feel so much like a chicken after that.
Like the saying goes: Making the summit is optional. Making the basecamp is not.