Chiba Workers’ Mountaineering Federation (Chiba Rōsan) is a regional mountaineering organization founded in 1967 by five clubs and affiliated with the Japan Workers’ Mountaineering Federation. As of March 2025, it brings together 15 member clubs with 632 members across Chiba Prefecture. The federation supports a wide range of climbing and hiking activities, helping members develop their mountaineering skills and promoting safe practices in the mountains.

Its programs include safety and technical training, such as rope-work, snow travel, tent-based trips, climbing, rescue and search exercises, as well as lectures and online courses. Hiking activities and overseas trekking are also featured. Beyond member services, Chiba Rōsan works to meet the interests of local hiking and mountaineering enthusiasts and to protect the region’s natural environment.

In cooperation with local authorities, it organizes clean-up hikes to remove litter from the mountains and streams of Bōsō. The federation also shares activity reports, regional mountain information, safety resources and news through its website and committees