How much is a 1921 Shrine of the Redwoods silver dollar in very good quality worth with Lady Liberty on one side and a horseback Indian on the other?

Not sure just what you have, but it sounds like a souvenier piece that would have been sold at the shrine and not a silver dollar. It is possible that the reverse of a real silver dollar was filed off and the Indian portrait was added by some private company. It would not be something that would be listed in any numismatic value guide, so the only way to find out what it is worth is to advertise it for sale and see what offers it brings.