Sapo is genuinely remote. The standard approach is from Monrovia via Buchanan and Greenville — a journey of at least one (probably two) long days by 4x4, with the road south of Buchanan progressively deteriorating. From Greenville, it is several more hours of rough driving to Juarzon or Jalay's Town on the park edge.
In the rainy season (May–October) the route is often impassable and trekking inside the park is hard going. The best window for a visit is the drier months from December to March.
All visitors must have a permit and a guide arranged in advance. Contact the Forestry Development Authority (FDA) in Monrovia, or work through the Society for the Conservation of Nature in Liberia (SCNL) or an established eco-tour operator. Do not turn up unannounced.