Above, the Rockies rose hundreds of feet in the air. If you can justify using a comma for any of the above reason, you should be safe. If not, don't use one. For the remaining comma rules, consult a good handbook. They are not, however, interchangeable in their usage.
Colons are a more formal pointer, and they have special usage in joining two independent clauses.
They are often used after a complete sentence to introduce a quotation, a list, a summary, or a restatement. Dashes are formed by two hyphens without spaces. Dashes are less formal, and they have special usage in setting off abrupt interruptions to the main idea of a sentence. Most people have no trouble with the first kind of usage, but they do get confused about where to put the apostrophe when showing possession. In showing possession, we always put the apostrophe after the base word.