Thanks to everyone who helped me plan my trip. The information you gave me really helped a lot and I had a really successful trip.
I thought that it might be useful to others reading here and maybe just for contributors interest for me to write some kind of trip report, so here goes:
I managed to book transport via Amtrak from Palm Springs to Curry Village and then back to LA. It worked out surprisingly cheap considering the long travel time. $74 out (7am to 8pm), $58 return (9am to 7pm). I was concerned initially about how much luggage i would be able to take on the Amtrak bus that took me from Palm Springs to Bakersfield (to get the train on to Merced) as the size restrictions were pretty close to what I had, but the bus driver was really cool and really wasn't bothered.
Setting up my tent in the backpackers camp was no problem, there was maybe only 3 other tents there and there is space and bear containers there for maybe 40 tents. In the morning, I packed up and intended to move on to Camp4 so I could spend a few days getting to know the valley by doing some day trips. I walked over to the visitors centre and was blown away by the amazing views that I had missed on the way in in the darkness the night before. My intention was to get my wilderness permit to start in a few days time, but it turns out, you can only get your permit for the following day. As I was right there, I just decided to start my hiking trip the next day and have more time to hang around in the valley when I got back. I picked up my bear canister ($5 for the week plus $95 cash deposit or no deposit if paying by visa) and permit and then headed back to the backpackers camp. I hurriedly dumped my gear in a bear box on the camp site so I could make may out and get a proper day's hike in.
I did a great days route, up to Mirror Lake, up the 100(?) switchbacks and then over towards North Dome, then back via Yosemite Falls and down the Yosemite Falls trail, walking back along the valley to the backpackers camp. I started about 11.30am and ran to the 2 miles bottom of the switchbacks to make time. It was surprisingly hot (25 degreesC or so) and strong sunshine and there is very little wind. The ground was bone dry and pretty rocky with the rock being pretty light in colour so I felt pretty baked going up the switchbacks. I saw loads of lizards and almost shat myself seeing my first ever rattlesnake just by the path. I went to sit on a rock to calm myself and there was another right under that. I have never jumped so much. I spent the next hour terrified that on the other side of every rock i stepped over or walked past there was going to be another. Of course, I didn't see another snake for the rest of the trip and soon realised I was wasting energy being scared.
By the top of the switchbacks, I was entering shadier woods and it started to cool a bit. I started running again as electrical storms were forecast for the afternoon and I didn't want to be too high too late in the day. As I got out towards North Dome, there was already plenty of thunder and dark clouds rolling in. It was around 3pm and I decided not to bother making the dogs leg out to the dome. I was also feeling pretty tired (lack of caffein, water or altitude, I couldn't decide, but I felt shit).
Taking the path back to Yosemite falls was the first time I needed to get out my GPS (http://topomapsapp.com on iphone4 totally invaluable and much better than the standard map set that comes with a garmin, it would seem). For the most part, the paths are pretty obvious, but they often cross bare rock. On popular paths these sections are well marked by lines of boulders but sometimes not. The paths in general zig zag a lot to avoid steep bare rock sections and try to keep a gentle gradient for pack animals, so one has to be very aware of changes in direction. Often there are rainwater drainage channels contracted across the path and these can be confused for a switchback and in the dark or snowy conditions really cause confusion. Walkers are actively told NOT to make way markers or cairns, which seems a bit mad to me as on certain sections, they would have helped a lot. I soon realised that looking for cut log ends, where downed trees crossing paths had been cut by rangers, to make way, was a great path marker when the path was buried under 2ft of snow. There is also a system of cut marks in tree bark. Some may be a couple of lines, some diamond shaped (and others I assume). Someone told me there were different systems made by army or loggers or someone, I forget the details now. Anyway, I found myself resorting to GPS to find the exact route of the path much more often than I would have expected. In the UK it's usually cloud and mist that makes navigation tricky, but all the above and the virtually constant trees was the issue here. The maps generally have very few features marked on them compared the British Ordinance Survey maps, so I found GPS a massive help in the conditions I faced later on in the trip. To be honest I would have been struggling without it. Maybe people with orienteering skills would fair better.
The next day I set off on my big trip with my big heavy bag. one word of caution to people who haven't carried one of the bear proof food canisters before, don't make the same mistake as me: I figured as my food was the densest thing in my bag, I should pack it at the bottom of my rucksack. Bad news. The bear canister is like a small barrel about 10-12" high. Just about the shittest shape to pack efficiently in a rucksack. I put it horizontally at the bottom of my bag. the problem was that the wider middle pressed into the base of my back where my trouser waste band was. It was unnoticeable at first but after a sweaty 10miles, climbing up to Nevada Falls, I was starting to feel like i was losing a small patch of skin resulting me walking the next 8 miles somehow trying to push my hands between my waist belt and my back. It seems a better position for the canister is higher up at shoulder height, though this does make your pack pull a lot more on your shoulders. Maybe I should have tried to strip down on weight a bit more, a 35kg (80 pound) bag is really no fun, but I was really glad of all the stuff I had later on as conditions worsened.
Again the weather was really hot for me (25 degrees plus) and I set off early to get to Nevada fall and the majority of the climbing out of the way before midday. The Mist Trail is a lovely walk and though it was quite busy with people it was still great. I imagine later in the season it might be a bit overcrowded. The surface is asphalt for the first section then a mixture of built rock steps and good paths. No route finding difficulties here at all. After lunch at Nevada fall, I continued on up to Merced lake. From that point on, I saw only 1 person! So as soon as you are away from the day traffic, you really start to feel alone. The walk from here is a lot more flat and through lovely woods. Unfortunately there was a 3 to 5 mile section where a large fire has hit, though it did create an interesting, eery atmosphere. I found that the tracks through the woods had quite a deep grit on them, almost like walking through deep course sand. Slightly energy sapping over the day, but also small amounts would kick up with each step and land in the back of my boots creating a pretty abrasive powder that threatened to cause blisters. I have never suffered with those boots before then.
The continued walk on up to Merced lake was beautiful, but very tiring with that bag. Some amazing views at Bunnel Cascade. The weather had started to cool and I got caught in a brief rain/hail storm, but it brightened up again. Unfortunately my plan to swim/wash in Merced lake before my evening meal was scuppered by another hail storm that came in just as I had put up my tent. I pitched my tent right by the lake edge which I read later may not be allowed. There is a camp ground with bear boxes in the woods near the High Sierra Camp, but I really wanted a picturesque spot.
There was more hail/snow overnight, but only a light sprinkling yet the ground was still frosty in the morning. The morning sun was hot, though and I warmed up quickly.
My route this day was just a day hike up Fletcher Creek up to Vogelsang High Sierra Camp, over Vogelsang Pass and back down to Merced Lake through Lewis Creek. I left my tent and as much weight as I could by Merced lake and set off, meeting a ranger and his mucky-faced colleague on horseback just by the camp-ground. I felt slightly interrogated, but I suppose he was just doing his job even if it was in a bit of an officious way. He just asked if I had a permit and a bear canister, where I was going, which trailhead I'd started at etc. He didn't ask to see any evidence. I didn't see any other people for the next 3 days. Again, it started of really hot, but by midday it was starting to could over and by the time I had reached Vogelsang High Sierra camp at 2pm, it was snowing. Heading up from the camp over to the pass meant crossing lying snow which meant I lost the path immediately and using GPS was necessary, though the route was pretty straightforward and the cloud, though descending was not really too bad on visibility. The snow was around 10" deep so impeded progress a bit. I was used my lightweight crampons (http://hillsound.com/hillsound-product/trail-crampon/) for the first time. It is hard to say if they were helpful or not at this point. They gave more security when I had to negotiate snow over steep smooth rock sections when I went off path (treacherous without crampons) but they balled up so easily in this snow that they caused problems in other sections. I guess the reviews were right. I'm sure I can fashion some simple anti-balling plates, though.
Coming over the pass was pretty simple, but it's quite steep down the other side and the path was really unclear. I didn't want to go cross country and find myself trying to descend steep smith granit, so finding and staying on the path was pretty essential. I'm not sure if my GPS was out of whack here or if it was the map background that was inaccurate, but the path I followed was some distance (30m) from where I expected to find the path and it appeared to continue up towards fletcher peak (from the south side). It seemed like it may have been a newly laid path and my map was just out of date. The snow was coming down much harder now and I kept the pace pretty high so I could lose as much height as possible before the trails became hard to see under the snow. It wasn't such an easy route to follow but I made it back to Merced lake without incident feeling a bit soggy.
The next day was a cold but sunny start again. I headed up the Merced River towards Washburn Lake and later on towards Red Peak Pass. I decided to go for a wash and a swim in the river while the sun was out so I'd have chance to warm up again and my clothes dry out a bit. It felt great, but a little bit chilly, I have to say! The lake might have been a little warmer.
I had planned to camp by a small lake at 9860ft just south of Red Devil Lake. I was making great time after my 'rest-day' starting the final climb leaving the path intersection at triple peak fork at around 4pm. I should have been camping at about 5pm, but the increasing snow lying on the ground and the less distinct path started to cause more problems. Those last 3 miles took me at least 2 hours and I was quite ready for a rest.
The camping spot by the lake (frozen) was beautiful and I wasn't the first with the same idea as there was already a small fire pit (not that I was having fires). It was pretty much the only section of snow free flat ground that i could be bothered to look for at that time, though. I was slightly intimidated by the cloud that was stuck over Merced Peak, Red Peak and most importantly Red Peak Pass. The wind was a little stronger now (though not by UK standards) and it started to snow again as I quickly made some food. As I went to sleep, the snow was getting stronger and when I woke later in the night, I realised it hadn't stopped even though the noise had. It was just collecting on top of the tent and insulating the sound. It was my first time camping as high as that and also in the snow, so it felt pretty exciting to have to go and clear snow off the tent at 2am. I decided to review my plan to cross Red Peak Pass in the morning depending on the conditions. I knew snow was forecast, but my weather report was now a good few days out of date and I thought the worst of the weather should actually have already passed.
By morning, the cloud cover had not changed really with it coming down to possibly around 10700ft (so around 300ft below the pass). I took my time that morning hoping the weather would clear. The sun came out on me helping me dry out my wet tent, but it didn't shift over the pass. In the end with the positivity generated by a good cup of coffee and the desire to not be beaten, I decided to go for it safe in the knowledge that even if I had to retreat and camp at the same spot again that night, I'd still have 3 days worth of food left to retrace my steps and maybe take in another day loop.
I probably set off around 11am that day and didn't really bother with the futility of trying to follow a path. It was buried under a foot of snow and since there were few/no trees now, it was just a matter of making my way up to the pass. I felt much more at home now. This was like many winter walks in Scotland. Just plowing through a blizzard with goggles on and using poles to keep balance and move steadily. The snow was getting deeper and deeper the higher I got and by the time I was on the steepest final ascent to the pass which should have been a path with switchbacks, I was struggling through 3ft of powder. The visibility was about 10-20ft now and i was feeling pretty disorientated. Needless to say it was exceptionally hard work to make any progress and I felt the altitude may have added at least a little to that. In the thick cloud I managed to make a slight navigational error rather than reach the actual pass, I made it to the dip in ridge line a little closer to Red Peak. The way down on the other side from that 'pass' looked like certain death so I was faced with 3 options: climb the stegosaurus-like ridge line to the actual pass, traverse the rocky section or descend the re-ascend to come around below it on the deep snow. Thoroughly exhausted, I decided to go for the traverse which was actually followed by a 30ft down-climb. This shouldn't really be anything worth writing about, but given that I was alone, very remote and the conditions and that I had a huge pack on my back, i took it very seriously. A slip here would have been very serious indeed. Needless to say, I made it and I was very pleased indeed to see the switchbacks that ran down the other side of Red Peak Pass. I had figured that since the switchbacks were on the windward, South side of the pass that there would be no where near as much snow there and the path should be more obvious. If I was wrong the avalanche risk would have been considerable and finding the route through the rocks and crags would have been tricky.
From this point on the route past Ottoway lake was beautiful, though the cloud and snow didn't lift. I decided to camp by the path intersection by Upper Merced Lake as I was worn out and it was already getting dark.
The next day I had planned to camp somewhere in the Illouette Valley, but when I woke at 7am, I was panicked to find the tent squashed 6in from my nose under 2ft of snow that had fallen overnight. Id been too lazy to get up and clear it this night. I'm happy my tent held, though a couple of poles suffer a slight extra bend now. It's a great 4 season Hilleberg tent (http://hilleberg.se/product/tarra) but the large flat roof sections don't shed snow as well as they should, possibly exacerbated by the external poles that stop the snow from sliding off easily. It is unbeatable in strong winds and is exceptionally fast to put up as the inner and outer stay attached together and are put up as one and are just clipped to the poles after they are slotted into their half sleeves. It's also great in hot weather as there is a huge door at either end so there's a great breeze that blows through. It's probably a little heavy for single person use, however. I was pretty glad of the security on this occasion, though.
Given the increasing and persistent snow, I decided to make a fast exit before the going got even harder. My breakfast was a snickers bar while I walked and I forewent the morning brew. I had at least a 16mile walk (if I didn't get lost) through 2ft high and rising snow. Nedless to say, I lost the path after the first minute of walking. Half an hour of frustration and constant GPS consultation followed trying to negotiate sensible places to cross now swollen and very cold looking streams. At this point I was beginning to calculate how long the walk back to Yosemite Valley might take me if things continued like this and I was depressed by the prospect of struggling through this for the next 15 hours. And then, from somewhere, I have no idea where, some footprints appeared. Judging by how filled in they were, they had been laid an hour or two earlier so someone had been up early, but they were going my way and whether they were following the path exactly or not, they were far quicker to follow than constantly consulting my GPS. Whichever superhero had laid this tracks for me, I am so grateful to. As it continued to snow, I kept the pace as quick as I could and didn't rest as I didn't want the tracks to fill in. Unfortunately, I never caught up with the person who made them. I have no idea where they came from as I was camped right at the intersection and I wan't aware of anyone passing when I got up, so it's a bit of a mystery.
A few tiring hours later, the tracks gained another set of prints and I finally caught up with the two guys who'd made those. They had parked up the night before on the Glacier Point Road near Mono Meadows, walked in a 6 miles or so and camped, but had decided to turn back the next day after all the snow. They were super kind and offered to give me a lift back to Yosemite Valley so that I could knock a few miles off that days walk. I was just as glad of the company and good cheer they had. The walk was still bloody hard work and according to my GPS watch was actually 18miles that day. It also involved a boots-off river crossing in bare feet which was, surprisingly, another first for me. The river felt warm compared to walking around in the snow and icey gravel on the riverbanks. It was pretty damn painful, but kind of fun, too.
Thankfully when we got to the car, the Glacier Point Road, though closed to traffic, had been ploughed and the rangers had left the code for the gates under the windscreen wipers. Still, the 60ft out of the carpark was deep in snow and we spent a good hour clearing a path for the car. Bald tyres didn't help much, but the kind passing cyclist more than compensated for the lack of traction the car had.
I have to say that the cold bottle of Lagunitas that my new friends gave me was probably the best tasting beer I have ever drunk!
The views from the road back into Yosemite Valley on this day were so special. There was a little cloud hanging in the valley and it created such an amazing scene. My photos didn't do it justice, but there were enough photographers out that I'm sure there are many around to be seen on the web.
The next days in Yosemite valley were spent enjoying the hot sun, pizza and beer in Curry Village with a great run up El Capitan and Eagle Peak. I was pleased to meet another couple of Brits doing some fell running whilst there. Eagle Peak is probably the most exciting view point I have ever been to. No words describe how amazing it is, but if you haven't been there and you get the chance to go, it is so worth making the extra few miles from Yosemite Falls.
This was the day that I also discovered the free showers in Curry Village (bring a towel or drip dry). It was certainly preferable to washing in the river.
If I was to go back again, I don't think I would really change how I did it. I thick the time of year was perfect or at least I was lucky, despite the most snowfall the whole season. In summer, never mind the crowds being unbearable and the permit system being so retractive, but the heat would have totally killed me. Being on any of the climbs out of the valley after 11am was such a killer. When I was running down the Yosemite Falls path in the afternoon, the heat was killing me, I have no idea how the people coming up were coping. And summer??? That's just insane, you'd be cooked.
Now I'm back in the UK, I'm enjoying the cold and the rain again. I might get bored of it soon and be back, though.