On audit an examiner will consider the degree to which you have documented your business use. This will include not only your flight logs but receipts, meeting records, and other evidence of the business purpose for the plane. Duration also plays a part, especially for “mixed purpose” trips to pleasant destinations. The “predominant” purpose for a trip must be for business, that is, at least the majority of the majority of the days must have been spent on business activities, documented as such. For example, your trip to Telluride might have both business and personal pleasure aspects (it should). Just be sure that you can articulate the business aspects of this trip.