Locals are fond of repeating that on Kamchatka 'there are no roads, only directions.' You will have a hard time getting 'out there, ' where the bulk of Kamchatka's glory is (volcano bases, rivers, geysers), without an arranged 6WD truck or helicopter (or several-day hike). Daily buses do go between Petropavlovsk and Paratunka, as well as north via Milkovo to Esso.
Used by vulcanologists and travellers alike, Mi-2 (capacity: six or eight people) and Mi-8 (capacity: 20 people) helicopters charge by time travelled in the air (usually about R40, 000 per hour, plus a set pilot fee). An hour or so in the air (return) costs around US$200 per person in a group of eight or ten. Rides can be exciting (and loud) with windows you can open and room to roam about. Some travellers have complained that some trips adhere to strictly predetermined times at stops, but we had no problems.
Tour agencies can help arrange both helicopters and suitable road transport.