For gravel applications, a mountain bike mini pump is the best solution.  The wider body delivers higher volume with less effort than a road pump.  The MSW Airlift 220 has a full alloy body with cross-hatch texturing to ensure you get a firm grip even with wet or muddy gloves.  A 5" hose extracts from the body to provide flexible access to the valve stem.  The smart head works with both Presta and Schrader valves, and pumps up to a more than ample 80 psi.  The pump include a mount with 4mm bolts for tidy storage behind a bottle cage.