Cessna 402/402C/B379 Businessliner/Utiliner
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Communication Breakdown
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control
Flight Crew Returned To Gate
Procedure; Weather; Human Factors
First Officer loaded bags and then 2 passengers. We then had the aircraft de-iced due to existing ice on wings. We started aircraft per procedures with Gate Agent/Company. We followed aircraft appropriate checklists and then listened to ASOS for current weather. We then made a radio call on CTAF of our intentions to taxi to runway.Ramp area and entrance to taxiway leading to runway had been plowed. We continued to taxi toward runway until we slid about approximately a foot to the right of the center of taxiway and I applied brakes to stop aircraft. Upon inspection while stopped inside aircraft; we noticed a snow pile on right of taxiway between centerline and edge of taxi way. We then asked passengers if they were harmed. No one on the plane was injured or harmed. We then called on Company frequency and shut down both engines. We waited to have the aircraft to be towed to the hangar. Passengers were unloaded to the FBO shuttle that met them at the aircraft.Maintenance vehicles came over immediately after aircraft was stopped on taxiway and we were unable to disembark and they began to remove snow pile on taxiway in front of aircraft; prior to us inspecting aircraft. No damage obvious damage to aircraft. Very poor plowing technique. Taxiway entrance leading to Runway 35 was fully plowed. After approximately 100 feet; snow pile existed on right side of taxi way; upon exiting and inspecting aircraft and taxi way after the event.The taxiway was inconsistently plowed and nothing was NOTAMed and/or on the AWOS and Maintenance vehicles who were plowing on the CTAF had not alerted us of any snow piles or plows following taxi radio calls.  Establish two way radio communication with Airport Maintenance from snow plows that all snow and debris and equipment are clear of taxiways and runways.In the event of no equipment or personnel; make sure Airport Manager NOTAMs all airport and runway conditions as required for safe operations.
Air taxi pilot reported stopping on the taxiway due to remnant snow on the taxiway.