ANNOTATION: This article provides several harvest cost estimation methods for forest managers. Methods discussed include elements of stump-to-truck timber harvest cost estimation methods in ecosystem restoration prescriptions. Particular attention is focused on cost estimation models for tractor and skyline systems in Montana with additional focus on cost variances incurred at different tree diameters and skidding/yarding distances. ABSTRACT: Forest managers are constantly faced with the need to reliably estimate harvest costs. Because of the inherently variable conditions under which logging occurs, estimating costs inexpensively is challenging. Yet cost estimates for timber harvest are especially important as new treatments aimed at ecosystem restoration are developed. The approach presented here combines elements of several cost-estimation methods to efficiently estimate stump-to-loaded-truck timber harvest costs for a range of ecosystem restoration prescriptions. This approach relies on detailed information from logging managers to build predictive models. Two equations are presented, one for tractor systems and one for skyline systems in Montana. Stump-to-loaded-truck harvest costs are expressed for harvest volumes ranging from 13 to 125 green tons per acre, for timber ranging from 6 to 10.5 inches in average diameter, and skidding/ yarding distances ranging from 600 to 1,800 feet. The equations explained more than 60 percent of the variation in costs, with removal volume, average piece size, and average skidding/yarding distance as highly significant explanatory variables. For tractor and skyline systems, estimated harvest costs decrease $1.27 and $1.31 per green ton with each 1-inch increase in average diameter, decrease $0.06 and $0.13 per green ton for each ton increase in volume per acre removed, and increase $0.69 and $1.26 per green ton for each 100-foot increase in skidding/yarding distance, respectively.