set<Id> acctIDs = new Set<Id>();
    for (Opportunity newOpp : newOpps) {
        acctIDs.add(newOpp.Install_At__c);
        acctIDs.add(newOpp.AccountId);
    }
    Map<Id, Account> accMap = new Map<Id, Account>([SELECT Id, Region__c, System_AM__r.name
                                                    FROM Account
                                                    WHERE Id
                                                    IN : acctIDs]);

           if(accMap != null){
            if(accMap.get(newOpp.Install_At__c).Region__c != null)newOpp.Install_at_Region__c = accMap.get(neOpp.Install_At__c).Region__c;
            if(accMap.get(newOpp.Install_At__c).System_AM__r.name != null)newOpp.System_AM__c = accMap.get(newOpp.Install_At__c).System_AM__r.name;
           }
          System.debug('accMap' + string.ValueOf(accMap));