2000 H1 suddenly steering locked up while moving. very difficult to turn with engine on , will turn smoothly with wheels up and engine off. Brake is hard and feels like bubbles underfoot when applied . Previously the brakes stopped working then came back on . I tested the hydraulic unit and had one when this happened so intalled it , no improvement on steering . I think the brake problem will be solved by purging air .On the steering I have greased all components (yes I got the column) and am going to flush again . I guess the gear valve is screwed up . Any ideas?

using only electronic key or the metal key.(feature)
got park assist option?
a no key slot ignition, fails we scant the PCM for cause.

the steering is first. so wheels against curb or hard rock>?
front tires are free of objects?
to unluck it , try both key car came with new
and grab the wheel and move it CCW/CW roughly to free the key.
shifter is in park I guess. try Neutral? step brake
release hand brake, and shift to N
then unlock wheel. this answer is flat ground answer only

the steps are here
Check that the parking brake is set.
Check that the shift lever is set in P.
Sit in the driver's seat and firmly depress the brake pedal.
The "ENGINE START STOP" switch indicator turns green.
Pressthe"ENGINESTART
STOP" switch
if steering lock fails the books states

The "ENGINE START STOP" switch indica-
tor will flash in green and a message will be
shown on the multi-information display. Press
the "ENGINE START STOP" switch again
while turning the steering wheel left and right!!
read page 137

https://assets.sia.toyota.com/publications/en/om-s/OM53839U/pdf/OM53839U.pdf

Can you turn the key? Some makes and models, if the steering wheel is causing tension on the key cylinder causing it not to turn, Sometimes you can pull ******* the steering wheel, one way or the other, to release tension on key cylinder in order to turn the key. Once you turn the key, steering wheel releases, hopefully.
If you can turn the key, turn to acc, set parking brake, step on the brake, hopefully then you can shift into neutral. That should bypass shift interlock. This info may be in your owners manual?

double posted read post 1

if you turned the steering wheel after shutting off the engine and the steering wheel caught the lock and tried to turn back it would hold pressure against the ignition lock cylinder. if it happens again try pulling the steering wheel hard one way or the other and turn the key at the same time.

if your key is a transonder key wich has chip in it give it a couple of minutes to reset the code keep key in ignition and wait to see if it reads key or try another key and see if you have sameproblem make sure you unlock steering wheel disconnecting batteryfor posts might have reset car computer and cannot read ur key...

Try turning the steering wheel (hard) right and left while turning the key. Steering lock , and ignition lock work in conjunction with each other.

it may be your steering lock try and move the steering left and right whilst turning the ignition or an old car thief trick is just keep pull down to one side on the wheel until the steering lock snaps or shears and it should be free to turn after that good luck

Make sure to push the brake firmly with you foot. I do this all the time.

Yes it does sound to me like the key is the problem.
the only other thing for a steering locking up would be the steering lock silenoid but that is activated by the brake pedal and the key has to be turned
if this is the orginal key it could be something else because the key and the tumblers inside the ingintion would wear down the same time together,but is the is a replacement key or back-up it will be the key because the tumblers would have been worn done by a different key.
try wiggling the key as you turn maybe you can get it to turn.
You will likely have to replace the ignition and key together.

The steering lock consists of a hardened pin and it may not be releasing any more although it shouldn't interfere with the turning of your key, just your steering unless the Geo is done differently.
If it was mine, I would get a little rough with it and turn the steering wheel hard from left to right while trying to turn the ignition key. 
Even disassembly is not easy since the lock area is supposed to be secure so it cannot be easily defeated.