Clackamas rhymes with:
anonymous, artemus, autonomous, blasphemous, hippopotamus, infamous, magnanimous, monogamous, polygamous, pusillanimous, synonymous, thalamus, unanimous, venomous
Clackamas sounds like:
calgene's, calkins, callousness, caulking, caulkins, chalking, clashing, classing, clausing, clicking, cloaking, clocking, clogging, closeness, closing, closings, clucking, coalescence, coalescing, collegians, collisions