Complex sentence: At their height, the Pacific Coast Militia Rangers consisted of 15,000 volunteers in 138 companies under three major patrol areas, which were Vancouver Island, the lower Fraser Valley and the Bridge River area.
Split into simpler sentences: At their height, the Pacific Coast Militia Rangers consisted of 15,000 volunteers in 138 companies. The PCMR was composed of 138 companies under three major patrol areas, which were Vancouver Island, the lower Fraser Valley and the Bridge River area.