Denton was appointed as Lieutenant Governor of the Colony of Lagos in early March 1900,[3] but in November of that year was reassigned as Administrator of the Gambia.

As Governor, Denton completed the work began by his predecessor, Robert Baxter Llewelyn, in establishing the framework of British rule in the Protectorate.

Denton also successfully argued against the requirements of the Entente Cordiale, which would have assigned a mid-river port on the Gambia to the French.

Denton also made a contribution to domestic politics in the Gambia, appointing S. J. Forster Jr, to the Legislative Council in 1906.

According to his obituary published in The Times he ensured that "considerable progress was made both in the condition of the [Gambian] people and in trade.