To simplify the expression \( \frac{a^{67}}{b^{34}} \), you can simply rewrite it as it is already in its simplest form:
\[ \frac{a^{67}}{b^{34}} = a^{67} \cdot b^{-34} \]
This is the simplified expression. It indicates that \( a^{67} \) is in the numerator and \( b^{34} \) is in the denominator.
If you are looking for further simplification or if there are any specific values for \( a \) or \( b \), please provide them! Otherwise, this is the simplest way to express the fraction without any additional context.