I'd look for either Sequoia sempervirens 'Kelly's Prostrate' or 'Cantab'.

The Sequoiadendron giganteum 'Pendulum' Gets 20-30 ft tall and will stay very narrow.

Sequoia sempervirens 'Cantab' is a slower growing but otherwise normal habit, predominantly or entirely single trunked Coast Redwood tree. For instance one in Seattle was 59 1/2 ft. tall in 2015, another one there 55 ft. tall. A third, in Britain, was 66 ft. tall in 2010.

The rooted side-branch version of it seen in nurseries is 'Prostrata'. This starts out as a mound but often soon throws up leads and starts morphing into 'Cantab' unless these are kept pruned out.

Sequoiadendron giganteum 'Pendulum' is no dwarf either, having grown over 105 ft. tall (2010) in Britain, with one in Seattle being over 50 ft. high by about 5 years later. And often this develops as a sort of giant octopus with multiple large hanging branches, so that even when not poking up to form a taller specimen like the two previous examples, it still occupies a lot of space, both physically and visually.

I've seen dwarf, upright form(s) of Sierra Redwood on the local market but their foliage had an unappealing, disheveled stringy appearance. As can be seen here.

https://www.forestfarm.com/product.php?id=4227

I don't know anything about this one, from their description presumably it gets beyond your cutoff in time. But maybe you would like to look for it anyway.

http://www.iselinursery.com/colorful-conifers/sequoiadendron-giant-redwood/sequoiadendron-giganteum-von-martin/

'Von Martin' is a gorgeous globe. There is a S. giganteum called 'Blauer Eichwerg' which is very blue and extremely slow growing. Also 'Little Stan', even slower and a variegated cultivar whose name escapes me. I have all of them, including the aforementioned 'Pendulum', which does get enormous. These things can be pruned, remember (although trying to keep 'Pendulum' from doing its thing would be extremely challenging!)

of course.. what they all said.. but i like to sum up the underlying concept .. along the lines of ... a dwarf of a tree that can grow 350 feet .. might only get to 200 feet in the same time frame ...

'dwarf' is just a term to mean a slower growth rate than the standard ... its all about the annual growth rate [if you can find it] .... it surely doesnt mean.. they will stay small.. given decades.. or centuries ...

ken

The pendulum literally looks likes a giant monster trying to grab you lol. So I guess most of the dwarf varieties are either prostrate or globe style plants.. not really a low growing tree. Cantab looks nice but too big lol

If you look at the Iseli link I provided the 'Von Martin' appears to be a slow growing tree with a leader.

I've had it for six years in the ground and no remote sign of a leader - it is almost a perfect globe. If it throws one, I will cut it off. And Heruga, yes, they are dwarf and not excurrent, at least not so far in my experience. What are you looking to achieve?

I'll second the recommendation for Sequoia sempervirens 'Kelly's Prostrate.' I have one that is happily growing laterally not a foot off the ground. I would say it adds about five inches of width a year, and not even an inch of height.

No Sequoia or Sequoiadendron will do that, unless it is managed, a la bonsai.

That is lovely. Mine is bluer, but that might just be the photo. Mine was a freebie because the trunk had snapped off way down low and it only had one branch (I think that it fell off the truck). Now, 3-4 years later it looks like yours!

Looks like it has same Bad Hair Day foliage of dwarf Sierra Redwood cultivar(s) I have seen at outlets here.

If you look at the Iseli picture of 'Von Martin' it is a bit dumpy, as though it grew for a time without a lead. Other dwarf or slow-growing conifers may start as shrubs and then become trees over time also. Perhaps the most noticeable example is stock sold as Pinus strobus 'Nana'.

This one is narrow but will grow more than 6 in. per year. Probably some part of your criteria is going to have to be let go of if you are going to end up with a redwood at all.

https://www.forestfarm.com/product.php?id=4243

If you think that this is bad hair day foliage I suspect that you do not like Platycladus o. 'Franky Boy'!