Highpoints of Ghana, Togo, and Benin

Leklata (900m), Ghana Highpoint

Mt Atilakoutse (991m), Togo Highpoint

Mt Sokbaro (660m), Benin Highpoint

Dec 12 – 16, 2021

Eric, Kahler, Serge

Background

There are a handful of countries in the world where the country highpoint is not known with certainty. For these countries generally there have not been careful enough elevation surveys conducted to distinguish the highest point among multiple candidates of similar heights. 

Three such countries exist in West Africa: Togo, Gambia, and Guinea-Bissau. Each have multiple potential highpoints and they have not been surveyed carefully enough to definitively determine the true highpoint. To find these candidates I first found the highest peaks in each country within the error bounds of SRTM data (up to 16m [1] ) using Google Earth. I then researched elevations for each of these highpoint candidates for these countries based on nine different sources: 1981 Soviet Military ground survey [2], 1974 US Joint Operational ground survey [3], 1994 US Military ground survey [4], Google Earth SRTM [5], topographic-map.com DEM [6], floodmap.net DEM [7], ARCGIS [8], Peakbagger [9], and Gaia [10]. The results are compiled below. No peak is highest in all surveys for any country and all candidates for a given country are within the error bounds of SRTM measurements (the only source that has published error bounds). Thus it is not clear based on publicly-available data which contender is the country highpoint for each of these three countries.  We set out to survey these candidates carefully enough to determine the true country highpoints. The expedition took planning over several years and has been one of the most logistically complicated trips I have ever done.

Serge and I first planned a trip to climb and measure these peaks in March 2020. I had rented a Geo7x GPS unit capable of sub meter vertical accuracy and we’d bought flights, but then the Coronavirus pandemic hit and we had to cancel the trip at the last minute. The airlines gave us flight vouchers valid till Dec 31, 2021 for the same flights. 

By fall 2021 it looked like it would be safe and feasible to go for the peaks again and redeem our flights, but the trip would be considerably more logistically complicated. Our primary objective was to climb and take accuracte field elevation measurements of all the highpoint candidates of these three countries, but we also hoped to tag on other nearby country highpoints if possible. The problem was each country now had different covid restrictions for entry and exit, and these policies seemed to change by the week. 

In late August I was finally recovered from climbing in Kyrgyzstan over the summer and Serge and I started planning our West Africa trip again. Given the complicated and changing covid restrictions, I decided to come up with multiple possible itineraries, then by mid November we would pick the best one based on the covid policies in place then. 

This was a very complicated optimization problem. I first found and listed out the covid restrictions of all the countries in West Africa. I then researched maps of all direct flights between countries in the area using flightconnections.com. It would be much easier to meet covid restrictions for direct flights and would also save time. (Some countries have restrictions even for transiting, and I hoped to avoid this extra complication). I then researched all the highpoints we were interested in climbing, drawing on our previous research from 2020. 

Most of the peaks in West Africa have little or no beta posted online. I think very few tourists or peakbaggers visit these areas. So I had to build in extra buffer days to account for uncertainty in accessing and climbing the highpoints. I researched and listed out all the visa requirements for all potential countries, and found all the locations and turnaround times for covid tests in each country.

In early September there was a coup d’etat in Guinea and all the borders closed. It was unclear if the country would stabilize by December, so I had to come up with more alternative options. In all I had about a dozen possible itineraries to choose from. 

Serge was in charge of transportation and had found contacts in several countries who could help with ground transport. In general I’ve found in developing countries in africa it is cheaper and safer to hire a car with a driver than to rent by yourself. Self rental usually has a per-km fee, while hiring a car with a driver does not. There are generally many military and police checkpoints and the bribes to get through will be much lower with a local driver. Finally, a local driver will be more accustomed to driving in risky conditions (with huge slow trucks, motorcycles, pedestrians, and more vying for narrow roads) and will know which dangerous areas of the country to avoid. 

By mid November it looked like covid restrictions had stabilized and we were ready to settle on an itinerary. Multiple contacts in Guinea said the country had stabilized and travel was safe. Backup countries like Cape Verde became unviable when the domestic airline went out of busines. We decided the optimal itinerary was to first fly to Togo and spend four days there tagging the Ghana highpoint (Leklata, on the Togo-Ghana border), climbing and measuring the three candidate Togo highpoints, and climbing the Benin highpoint (Sokbaro near the Togo-Benin border). 

Togo required a PCR test seven days before arrival, then a PCR test would be taken on arrival at the Lome airport and we would have to isolate in a hotel until results arrived. They then required another PCR test before departure from the country for stays longer than five days. By staying four days we avoided this requirement. It would theoretically only take three days to hit all the peaks but a buffer day was wise to add due to additional uncertainty in the Lome PCR test turnaround time.

We would next fly to Senegal to access the Gambia highpoint candidates from the Senegal side of the border. Senegal required a PCR test five days before arrival and our test in Lome on entering Togo would count for Senegal entry since we would only spend four days in Togo. 

As soon as possible after arriving in Senegal we would get a PCR test in Dakar at the Pasteur Institute, which would allow us to fly to Guinea. While waiting up to 48 hours for the results we would climb and measure the Gambia highpoint candidates. (There would likely not be enough time for the Senegal highpoint, so we would access it from the Guinea side.) 

We would then fly to Guinea and stay there ten days, climbing the Guinea/Cote D’Ivoir highpoint (Mt Richard Molard on the border), the Senegal highpoint (an apparently unnamed peak on the Guinea border), and the two candidate Guinea-Bissau peaks (both on or near the Guinea border and both apparently unnamed). 

We would then return to Conakry two days before our departing flight, giving enough time to take a PCR test with 48hr turnaround time for us to return to the US. It was a complicated schedule but seemed doable and would give enough time with buffer days for uncertainty.

Then a week before departure the Omicron variant started making headlines and countries started closing their borders. The US changed its covid policy to require a negative test the day before departure to enter the US instead of 72 hours before departure. It seemed like we would have to cancel again since the only testing location in Conakry, at The Palais du Peuple, would not guarantee results of a PCR test that quickly. 

But I looked over the US entry rules more carefully and we could actually take an antigen test instead of a PCR test and use that for entry to the US with a vaccination card. I found online that emed.com sold at-home antigen tests that would count for reentry to the US if conducted in the presence of a tele medicine doctor. I bought a 6 pack for $150 and Kahler bought a backup pack. 

Serge still needed a PCR test to return to Canada, but he found an at-home PCR test for $150 from Lucira that would count. The trip was finally doable again. 

Lastly, I needed to bring a GPS unit capable of sub meter vertical accuracy to measure the elevations of the potential highpints. Phone GPS units are generally based on barometric pressure for elevation and can have dozens of meters of error, so those wouldn’t work. Handheld GPS units like my Garmin 62S are satellite-based for elevation and can get around 20m vertical accuracy. Neither of those options would be sufficient. 

Matthew and I had previously rented a Trimble Geo7x from Waypoint technology to determine the true highpoint of Saudi Arabia in 2018 (it’s Jabal Ferwa, 3m taller than Jabal Sawda). The Geo7x requires access to nearby base stations for sub meter accuracy, which is possible but not guaranteed. This unit is expensive to purchase (around $10,000 new), so it makes sense to rent.   

Unfortunately, Waypoint wasn’t able to rent out another unit this time. I contacted another company that would rent me a Geo7x, but it would be expensive and they wouldn’t be able to help with data post processing.

Then I heard back from Compass Data, and they very generously offered to lend me some equipment. They had a Trimble GeoXR with Zephyr 2 antenna on a tripod. If I set it up and took measurements for an hour I could get as good as 3cm vertical accuracy with no need for a nearby base station. That was perfect! 

The day before my flight the equipment arrived and I was able to take a test measurement outside my apartment to make sure I was using it correctly. Everything was finally in place to go forward with the trip. 

Dec 11

I finished grading my last SU final exams Thursday night, then spent Friday packing and practicing with the GPS unit. Then Saturday I left Seattle at 9:30am, had a layover in New York where I met up with Kahler and Serge at JFK, then we all flew together to Lome, Togo. 

Dec 12

We landed at 12:30pm and made it smoothly through customs. We then got the PCR test at the airport and stopped to buy a local sim card. I’ve recently discovered how cheap and easy it is the make a phone work like normal in another country. My phone was locked, but with a call to my provider just before the trip and a 48hr wait they emailed me the unlock code. I got Wifi in the airport in Lome and received the code just in time. Then I bought a sim card at the airport with several gigs of data for only $5, inserted that in my phone, and my phone worked like normal in Togo. 

Serge had arranged a 4wd SUV rental with Europecar and we went outside to pick it up and withdraw money at the ATM. The man at the counter warned us that there had recently been some unrest in northern Togo near the Burkina Faso border and we should be careful since we were planning to drive up near Kara. We decided it would be safest if we hired a local driver who would help keep us out of dangerous areas and help with bribes at checkpoints. 

We were required to isolate at a hotel in Lome until our PCR results came back up to 24 hours later, so we said we would drive ourselves that day then meet our driver the next day at the airport.

We drove to Hotel Ambassador, which I had reserved in advance on booking.com, and found a nice room. We had a lot of time on our hands that afternoon so I decided to practice taking a GPS measurement outside. I set up the equipment in front of the hotel and took a one-hour and a half-hour measurement by sunset. I sent the data to Compass Data engineers over email on my phone and they confirmed I was taking the measurement correctly. That helped boost my confidence for the rest of the trip. 

Dec 13

The next morning we slept in to try to adjust to the new time zone (eight hours difference for me), then ate breakfast in the hotel restaurant. By 9am we each received emails with negative test results, which meant we were free to go. 

We drove back to the airport and met our driver Fernando. French is the primary language in Togo, so Serge did all the talking since he speaks fluent French. (My French from college is pretty rusty so I’m super happy Serge was able to make it on the trip). Serge made sure Fernando understood all the places we wanted to visit and our mountain-climbing objectives for the trip, and then we hit the road. 

Our first goal was the east and west peaks of Mt Agou. Most sources cite Mt Agou West Peak as the Togo highpoint, but SRTM results show the East peak a similar height and another point on the plateau Danyi farther north also as a similar height within a few meters. We hoped our measurements with sub-meter vertical accuracy would be able to resolve which was highest. 

We rode a few hours north to just before Kpalime, then turned off on the road to Mt Agou. At the base we stopped at a small stand and paid about 10 USD each for a permit slip to go to the summit. Since the West summit is generally considered the highpoint we decided to go there first. We drove up lots of switchbacks and then reached a military checkpoint just before the summit. They checked our permits, then opened the gate and let us in. 

We drove around to the parking lot, which was just 10ft from the summit marker. I hadn’t realized it would be so easy. I quickly took out the survey equipment and set it up exactly on the summit. This involved setting up a tripod with the Zephyr 2 antenna mounted on top, leveling the atenna rod with a bubble level, mounting the GeoXR unit to the tripod and connecting it to the antenna, then going through some software to initiate a one hour survey. I also took pictures of the setup in the north, east, south, and west directions. The military guys wandered over and did not look happy with the tripod and weird looking equipment set up there. They talked to Serge and the driver and Serge tried to explain that we were measuring the elevation. 

 

I don’t think the military guys believed him. They talked a while more, then made some phone calls. Eventually they said we’d have to take the equipment down and get official permission from a government person in Kpalime to put it up again. Serge stalled them long enough that we got 30 minutes of measurements, but then I had to take it down. That was less than the ideal one hour measurement but still would hopefully give enough vertical accuracy to compare this peak to the other candidates. 

Unfortunately the military now told us we were not allowed to visit the East peak, even if we left the equipment in the car. That was very disappointing. In retrospect if we had visited the East peak first they wouldn’t have noticed the equipment since a trail goes there from before the checkpoint. But if we tried to go now we might get in very big trouble. 

We decided to move on and maybe try again in a few days if there were different guards. At least I knew that one climber, Chris Gilsdorf, had climbed both peaks in 2019 and his handheld GPS measured the East peak about 50ft lower. So there was a good chance it was not the highpoint anyways. 

We continued driving north heading for our next objective, the Ghana highpoint. Many sources cite the highpoint as Afadjato, a peak well inside Ghana. But SRTM clearly shows Leklata, a peak on the Ghana-Togo border, as at least 300m higher and definity the Ghana country highpoint. Highpinters are in agreement that Leklata is the true highpoint of Ghana. 

We followed beta from Lee Humphries and drove north through Kpalime then turned west on dirt roads to near the Ghana border. We parked at a small trail leading toward the border, then hiked up through grass and palm trees to the tree-covered summit just off the trail.

 

This highpoint was not controversial but I figured I might as well get a really accurate measurement of its elevation since I had the equipment. I set up the tripod and we waited for about 10 minutes, but then we heard people coming up the trail from the Ghana side. We got a little spooked about getting in trouble again so took down the equipment and headed down. In hindsight we probably could have taken the full hour measurement since it was probably just farmers walking by who wouldn’t have cared. I hoped at least the 10 minute measurment with that equipment might still be the most accurate measurement ever taken on that peak. 

Back at the car we still har plenty of daylight so continued driving north on the rough roads to our next objective, the Plateau de Danyi highpoint. We drove through the last village, Danyi Elavagnon, then reached the closest point on the road to the highpoint about an hour before sunset. Fernando parked at a pullout and we walked up a farmers field path for a bit then bushwhacked through dense brush to the summit about a half hour later. 

I took measurements on the highest boulder I could balance the tripod on, but there was a pointy boulder next to it that I used my sight level and tape measure to measure how much higher it was. I would use these to correct the GPS measurement later to be for the true summit.

 

This time we weren’t worried about anyone bothering us and got the full hour measurement. It ended after sunset so we had to bushwhack back in the dark. 

We noticed near the pull off there was a white sign that said Mt Atilakoutse 1030m. Serge and Fernando talked to a local walking by and he said this is the true highest peak in Togo. He said this area had been politically sensitive and off limits until just a few years ago. Government surveyors came in then and measured Atilakoutse to be taller than Agou and thus the true  country highpoint. Supposedly they didn’t make their results widely known because they didn’t want to have people change the widely-held belief that Agou was the highpoint. I hoped my measurements would be able to determine if this was indeed true. Unfortunately I would have to wait a while to post process the results to know for sure. 

That night we drove down to the main road at Amou Oblo and stayed at the Hotel Splendid. 

Dec 14

Our next objective was Mt Sokbaro. We left at 6am the next morning and drove north on good paved roads to Bafilo, then turned east headed towards Benin. Fernando said he had been in this area before, taking a tourist to some rock formations on the Benin border. 

 

We passed one checkpoint leaving town, paid a small bribe, and continued on deteriorating roads. We eventually wrapped down to the south side of Sokbaro and drove past a “Welcome to Benin” sign. A bit farther we saw a checkpoint, so we turned back into Togo and parked before the sign.

Fernando stayed with the SUV and we started bushwhacking up with Serge in the lead. I’d read a report from Lars Holmes from 2019 that he walked up a road on the Benin side to a radio tower on the summit. Unfortunately that wouldn’t work for us since covid restrictions made entering Benin complicated. But the peak was basically on the border so it seemed ok to bushwhack up from the Togo side. 

I was concerned since Lars had mentioned in 2019 there was a security guard at the radio tower. If the guard was unhappy with our measurement equipment we might get kicked off like on Agou. 

Interestingly, it is not certain that Sokbaro is the Benin highpoint. Another peak in Benin, Tanekas, is a similar height based on SRTM. (SRTM shows Sokbaro 656m and Tanekas 672m, just within the error bounds). It would be great to visit both, but since that one was deep in Benin we weren’t able to get it on this trip. I figured I could at least get a good measurement on Sokbaro and then maybe in the future I or another climber could measure Tanekas and figure out which is higher. 

 

Serge led the way bushwhacking. We roughly followed the border staying just on the Togo side, and reached the summit about an hour later.

Surprisingly the radio tower was gone and there was no security guard! All that remained was a dilapidated little concrete structure and an overgrown dirt road. This was great news for us. 

I set up the equipment for a solid one hour measurement. We noticed a boulder in the woods was a bit higher but too sharp to put the tripod on. So I used my sightevel and tape measure to measure the height difference to correct the gps elevation later. 

After an hour we returned back down. This time Serge found a trail leading to a col sw of the summit and then connecting nearly back to the road, so the descent was much easier. We made it back to the SUV with no problems and were soon driving away. 

This time we drove due west to route N1, avoiding the rough roads we had entered on. We just had to pay a small bribe at one checkpoint before we reached the main road. We later made it to Atakpame for the night. 

Dec 15

We were a bit ahead of schedule so decided to go back to Mt Agou and give the east summit another shot. We made it to the station at the base in the morning, but this time the man there said we were not allowed up. He said the military guys were mad at him for allowing us up before and that we needed official permit documents from Kpalime to proceed up the mountain.

Fernando said he expected it would take a significant bribe to get those documents and there was a risk they would confiscate the equipment if we tried. Also it could take several days, which we did not have. 

So we reluctantly agreed to skip East Agou and continue to Lome. The fact that the one gps measurement I know of measured East Agou shorter than West, and the fact that government surveyors concluded Mt Atilakoutse is the country highpoint make me pretty confident East Agou is not the country highpoint. Though of course it would be great if somebody can go and measure it to be certain. 

We made it to Lome that evening and stayed again at the Hotel Ambassador.

Dec 16

We had buffer time in the morning so walked down to the beach in Lome. The beach is surprisingly difficult to access and there’s a big intermediate zone of small farms between the city and the beach. I’m amazed there aren’t hotels lining the beach, but I guess Togo is not a major tourist hub. In fact, the only other white people we saw over our traverls were a few in the aiport.  

That afternoon we caught a 1pm flight to Dakar, Senegal to start the next leg of our trip, determining the true highpoint of Gambia. 

The measurement results are summarized below. Mt Atilakoutse is officially the highpoint of Togo. Note- these are given as PPP ellipsoidal height results with 95% confidence interval (RMSE), as processed by Compass Data engineers using Online Positioning User Service. Ellipsoidal elevation was then converted to EGM2008 orthometric elevation, which is the final result for elevation. Contact me if you are interested in more details of the post processing or would like to see the raw data.

References

1. SRTM Mission Statistics, Nasa Jet Propulsion Laboratory, [Online] Available at https://www2.jpl.nasa.gov/srtm/statistics.html [Accessed December 2021]
2. 1981 Soviet Military 1: 200 000 ground survey, [Online] Available at https://mapstor.com/map-sets/country-maps/western-africa.html#gs–200k–(1980-1983)–preview  [Accessed December 2021] 
3. 1974 US Joint Operational 1: 250 000 ground survey, [Online] Available at https://mapstor.com/map-sets/country-maps/western-africa.html#gs–200k–(1980-1983)–preview  [Accessed December 2021] 
4. 1994 US Military 1: 500 000 ground survey, [Online] Available at https://mapstor.com/map-sets/country-maps/western-africa.html#gs–200k–(1980-1983)–preview  [Accessed December 2021] 
5. Google Earth 7.3.4 (2021). [Online] Available at http://www.google.com/earth/index.html [Accessed December 2021]
6. Yamazaki D., D. Ikeshima, R. Tawatari, T. Yamaguchi, F. O’Loughlin, J.C. Neal, C.C. Sampson, S. Kanae & P.D. Bates, A high accuracy map of global terrain elevations, Geophysical Research Letters, vol.44, pp.5844-5853, 2017 doi: 10.1002/2017GL072874 [Online] Available at https://en-us.topographic-map.com/[Accessed December 2021] 
7. Floodmap Digital Elevation Model, [Online] Available at https://www.floodmap.net/, [Accessed December 2021]
8. ArcGIS World Topographic Map, [Online] Available at https://www.peakbagger.com/, [Accessed December 2021]
9. Peakbagger, [Online] Available at https://www.peakbagger.com/, [Accessed December 2021]
10. Gaia GPS, [Online] Available at https://www.gaiagps.com/, [Accessed December 2021]

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