DROUGHTS ARE ONE OF THE MOST DEVASTATING NATURAL HAZARDS FACED BY THE UNITED STATES TODAY. DROUGHTS MORE SEVERE THAN THOSE OF THE 1930S AND 1950S ARE LIKELY TO OCCUR WITH GREATER FREQUENCY IN THE FUTURE. THESE INCREASES IN DROUGHT FREQUENCY AND INTENSITY WILL BE ACCOMPANIED BY MORE INTENSE STORMS AND RECORD WET PERIODS: WITNESS THE RECENT MEGA-DROUGHT IN CALIFORNIA, BROKEN BY A YEAR OF UNPRECEDENTED RAINFALL. THE CHALLENGE IS NOT JUST COPING WITH DROUGHT, BUT ENSURING SUSTAINABILITY IN A FUTURE OF BOTH DROUGHTS AND DELUGES.THE NEED TO PLAN AND IMPLEMENT ADAPTATION STRATEGIES IS PERHAPS NOWHERE MORE URGENT THAN IN THE RANGELAND SECTOR. RANGELAND PRODUCTION SYSTEMS ARE GLOBALLY IMPORTANT AND HIGHLY VULNERABLE TO CURRENT AND FUTURE CLIMATE CONDITIONS.MANAGED GRAZING COVERS MORE THAN 25% OF THE GLOBAL LAND SURFACE, A LARGER GEOGRAPHIC EXTENT THAN ANY OTHER FORM OF LAND USE. IN THE US, 300 MILLION HA OF PUBLIC AND PRIVATE LANDS ARE RANGELANDS. RANGELANDS PROVIDE SOCIETY WITH GOODS (E.G., LIVESTOCK PRODUCTION/FOOD), SERVICES (E.G., WILDLIFE HABITAT, CONSERVATION, WATER QUALITY), AND CONTRIBUTE TO THE LIVELIHOOD OF MILLIONS OF HUMANS. HOWEVER, RANGELANDS ARE TYPICALLY LOCATED IN SEMI-ARID AND ARID REGIONS CHARACTERIZED BY LOW PLANT PRODUCTIVITY, HIGH PRECIPITATION VARIABILITY, AND FREQUENT DROUGHT. RANGELAND MANAGERS OFTEN HAVE LIMITED FINANCIAL AND SOCIAL CAPITAL, AND IN MANY CASES ARE REMOVED FROM POLICY MAKERS AND GOVERNING INSTITUTIONS.RECENTLY THE SUSTAINABLE RANGELAND ROUNDTABLE CONVENED UNIVERSITY AND AGENCY RESEARCHERS, PUBLIC AND PRIVATE LAND MANAGERS AND PRODUCERS, AND NON-GOVERNMENTAL ORGANIZATIONS TO JOINTLY CHART A RESEARCH AGENDA OF USABLE SCIENCE FOR RANGELAND SUSTAINABILITY. OUT OF 142 CHALLENGES THEY IDENTIFIED, "UNDERSTANDING AND MANAGING FOR VARIABILITY" RANKED FIRST. HERE, WE CONTINUE THIS COPRODUCTION PROCESS - INVOLVING INTENDED END USERS THROUGHOUT OUR RESEARCH ENTERPRISE - TO DEVELOP A FRAMEWORK TO ASSESS THE SENSITIVITY OF RANGELAND PRODUCTION SYSTEMSTO CLIMATE VARIABILITY AND IDENTIFY STRATEGIES TO IMPROVE THE ADAPTIVE CAPACITY IN THESE SYSTEMS.OUR PREMISE IS THAT STRATEGIES TO IMPLEMENT CLIMATE ADAPTATION WILL BE FAR MORE EFFECTIVE IF THEY ARE TAILORED TO LOCAL DIVERSITY IN EXPOSURES, SENSITIVITIES AND ADAPTATION OPPORTUNITIES FACED BY RANCHERS AND LAND MANAGERS.SOME RANGELANDS MAY SIMPLY EXPERIENCE LESS CLIMATIC VARIABILITY THAN OTHERS, EVEN IN THE FUTURE. SOME RANGELANDS MAY SUPPORT FORAGE PLANTS PARTICULARLY WELL-ADAPTED TO VARIABILITY, WHILE IN OTHERS FORAGE PRODUCTION MAY BE SENSITIVE TO VARIABILITY BUT LIVESTOCK OPERATIONS HAVE EFFECTIVE STRATEGIES FOR COPING WITH VARIABILITY. THIS PROJECT WILL CONSIDERDIFFERENCES IN VULNERABILITY AS KEY CONSIDERATIONS IN BUILDING ADAPTATION STRATEGIES.WE USE A COMPARATIVE FRAMEWORK THAT SPANS FIVE RANGELAND REGIONS WITHIN THE WESTERN US. OUR APPROACH COMBINES CLIMATE MODELING AND ASSESSMENT WITH FORAGE AND LIVESTOCK PRODUCTION MODELS IN A CO-DEVELOPMENT FRAMEWORK TO BUILD SCENARIOS ANDASSESS FEASIBLE, EFFECTIVE ADAPTATION STRATEGIES.THIS ITERATIVE PROCESS COMBINES RESEARCH AND EXTENSION TO SUPPORT A CO-DEVELOPMENT OF IDEAS, CAPITALIZING ON DIVERSE ADAPTATION STRATEGIES ACROSS WESTERN RANGELANDS. OUR OUTCOME WILL BE A STRATEGIC FRAMEWORK THAT REFLECTS THE DIVERSITY OF EXPOSURES, SENSITIVITIES AND CAPACITY TO ADAPT ACROSS THE WESTERN US, AND WILL RESULT IN A HANDBOOK, A WHITE PAPER AND INTERACTIVE TOOL CO-DESIGNED BY THE SCIENCE AND USER COMMUNITIES INVOLVED.