In the early part of the 20th century, Ecuador made an effort to peacefully define its eastern Amazonian borders with its neighbours through negotiation. On May 6, 1904, Ecuador signed the Tobar-Rio Branco Treaty recognizing Brazil's claims to the Amazon in recognition of Ecuador's claim to be an Amazonian country to counter Peru's earlier Treaty with Brazil back on October 23, 1851. Then after a few meetings with the Colombian government's representatives an agreement was reached and the Muñoz Vernaza-Suarez Treaty was signed July 15, 1916, in which Colombian rights to the Putumayo river were recognized as well as Ecuador's rights to the Napo river and the new border was a line that ran midpoint between those two rivers. In this way, Ecuador gave up the claims it had to the Amazonian territories between the Caquetá River and Napo River to Colombia, thus cutting itself off from Brazil. Later, a brief war erupted between Colombia and Peru, over Peru's claims to the Caquetá region, which ended with Peru reluctantly signing the Salomon-Lozano Treaty on March 24, 1922. Ecuador protested this secret treaty, since Colombia gave away Ecuadorian claimed land to Peru that Ecuador had given to Colombia in 1916.