1" is available but most OE rims on MTB are wider than you would want to safely run 1 inchers and not get snake bite punctures and dented rims.
Cannondale made that mistake with the first run of Bad Boy urban MTB's, 1" slicks on 1" rims, the results were not pretty.
Have you looked at Schwalbe Big Apples? it's a full volume MTB tyre with no tread at all and would work really well on hard pack tow paths.