Payments for ecosystem or ecological services (PES) are voluntary, often market-based approaches to protecting environmental values. In the rural United States, some landowners receive PES through government-led conservation programs, but little is known about their involvement in market-based arrangements. We analyzed three examples of market-based PES arrangements in northwestern Montana: watershed restoration and craft brewing, niche meat production, and certified timber supplies. We find that intermediaries were working between buyers and sellers in each case to set conditions for transactions and undertake the mechanics of implementation. These findings align with existing conceptualizations of intermediaries as crucial links in PES arrangements, but also suggest that intermediaries for market-based PES arrangements are not always facilitators or neutral nongovernmental actors; they may actually be from the private sector and drive the process by serving as buyers. This research contributes to a stronger understanding of the possibilities for local market-based conservation in the rural West.