Yes, this is seen in the case of Hashirama Senju, who mastered Sage Mode without the aid of any summoned beast. He was already able to sense natural energy due to the special connection he had with nature because of his Kekkei Genkai, the Mokuton (or Wood Release). There are other ways to master a diluted form of Sage Mode, too, as seen in the case of Jūgo's clan or someone who masters their cursed seals to the 2nd level, as seen in the case of the Sound Four, Kimmimaro and Sasuke at the end of the Sasuke Retrieval Arc. Finally, Madara Uchiha also gained access to Senjutsu chakra during the Fourth Shinobi World War by absorbing chakra from Hashirama Senju using the powers granted to him by the Ten-Tails and as a wielder of the Rinnegan without affiliating himself with any summons.