Understanding interlock yarders
By: by Ward W. Carson and Jens E. Jorgensen.
Contributors: Jorgensen, Jens E.; Pacific Northwest Forest and Range Experiment Station (Portland, Or.)
Series: Research note -- PNW-221.; USDA Forest Service research note PNW -- 221.
Publisher: Pacific Northwest Forest and Range Experiment Station, USDA Forest Service
Published: 1974
Place of publication: Portland, Or
Language: eng
Number of pages: 13
Subjects: Logging, Skyline -- Equipment and supplies.
Notes: Caption title.

"March 1974."