At first, Commissioner French was not very pleased with the appointment of Clark to the NWMP. He was not a military man - he was a relative of the Prime Minister. Clark was a meticulous man and ably suited to his new role, as paymaster for the NWMP. His work went beyond just keeping pay records, he also took care of purchases for the March West and later for equipping the posts.
When the NWMP set out on the March West, Clark and a handful of men were left behind at Fort Dufferin to take care of the numerous tasks involved with an army on the move. Later Clark did travel to some of the posts, and died unexpectedly at Fort Walsh in 1880.