Not from either of those places, but I am also from a large country, and second a bunch of the points made about the distance. I think, if you are interested in taking a road trip, Denver-San Francisco would be a cool one to do, but if you aren’t originally interested in a road trip per se, I’d maybe leave the road trip part for another time and just fly between the two places.
Extrapolating from my Canadian experience a bit, the train network is mostly used for freight outside of major cities, there are passenger trains on many routes but it’s not a common way to travel, and will be very expensive compared to what you’re used to in the UK. Between those two areas in particular it will be slower due to the elevation changes and indirect routes that have to be taken. In major urban areas though, train is absolutely fine.
As a fellow Commonwealth citizen, it’ll really help you when you’re on location planning your daily itinerary, to be able to check the weather in Celsius or easily convert. The conversion is inconvenient but something you don’t want to ignore, because neither place is much like the UK climate. Heat waves in the high 30’s in summer in California, and large daily temperature swings in Colorado depending on time of year, are probably the main things that could catch you off guard. If you’re doing a day trip at high elevations in Colorado, give yourself just a bit extra time because you might find it more tiring than at sea level, your body has to work a bit harder to give you the oxygen you need.
Maybe you could meet up with @Eke for a hike in California!
I could certainly help with any language barriers.
One thought of caution if planning something soon, @siand. Lots and lots of snow pack just fell on the Rockies. I know in California they’re at 250% of average for this time of year. Might affect some plans if checking things out up in the hills!
And trying to think… You might really like Tahoe for a quiet town vibe in the thick of some great hikes. Time of year is important depending what you want to do. The mid seasons (spring and fall) are better for hikes. And the snow will likely extend the snow/ski season. I’d actually love to meet y’all up there!
There’s Yosemite too, though that’s got fewer conveniences depending where you stay. And more people-y.
I am quite fond of Yosemite. Sequoias, mountains, waterfalls, trails of all ease and lengths. Some of the most beautiful country this great earth has to offer, and its easily accessible.
June is a good month, warm not hot. September too.
Its also a couple hours from the coastal redwoods!
There are, including protected indigenous lands, and sometimes info at conservatories and parks where applicable, and some cities and towns will have info or local museums. It depends where you go.
I was really lucky. My Uncle was the head Park Ranger at Yosemite for most of my youth. I got to stay right in the park at the ranger’s house. We got personalized tours and all the picks of the crazy things that bears do to campers and sites when people don’t pay attention to the warning signs posted all over the place. There was a cemetery right on his property. I don’t know if that house or cemetery are still accessible. I’d love to go back and see if I can find it.
It is! I was Googling it, too. I am pretty sure one of those buildings behind is the house but I don’t remember it being a village at the time. It’s been four decades, though. So, I’d have to tromp around a little to remember.
Also be prepared with clothes. Dress in layers. Consider the conditions of the trail, and how far you may be from food or water (both of which I’d suggest you bring in your backpack). Bring snacks / food that has energy: carbs, fats, protein (“GORP” is a popular trail mix snack: Good Old Raisins and Peanuts. You can add M&Ms if you want some sweet.) I like apples and cheese when I’m hiking.
Here’s some notes about dressing for hiking according to the weather:
The mountains and forests in Canada and the US are vast - truly vast - and depending on the trail you take it’s possible you may not see many other people. It sounds like you’re going to be near major cities so you aren’t likely to be truly isolated, but still it’s worthwhile to be prepared with food and a first aid kit - first aid kit “ingredients” here (scroll down):
If you have 3 weeks, I’d hit Yellowstone, too. Fly between each state. Driving an RV in the mountains can be tricky. If you do rent an RV, be aware that there are size limitations in Sequoia parks.
Yosemite has a limit on the number of cars allowed per day. You need a reservation to just drive in for the day.
Reservations (public and private) anywhere fill up quickly for all the parks in CA.
Enjoy!!!